# EOS 7D Mark II & Photokina



## Canon Rumors Guy (Aug 28, 2014)

```
<div style="float: right; margin:0 0 76px 0px;"><a href="https://twitter.com/share" class="twitter-share-button" data-count="vertical" data-url="http://www.canonrumors.com/2014/08/eos-7d-mark-ii-photokina/">Tweet</a></div>
<p>We’re <a href="http://www.canonrumors.com/2014/08/are-these-the-eos-7d-mark-ii-specifications/" target="_blank">standing by the specifications we posted a few days ago for the Canon EOS 7D Mark II</a>. We and others have received suggestions that the sensor in the camera is actually going to be 24mp, which contradicts the very solid evidence we have that says it will indeed be 20.2mp. What our information doesn’t specify is whether or not it’s the identical sensor to the EOS 70D.</p>
<p>If what we posted turns out not to be true, it will be the greatest hoax of specs that I have seen in the 6 years we’ve been around. I will release what we have in our possession after the announcement if it turns out we were wrong.</p>
<p><strong>Lenses at Photokina

</strong>We have nothing we’d call better than 50/50 on what lenses will show up for Photokina. If you know what’s coming, please let us know. <a href="http://www.sendanonymousemail.net/" target="_blank">You can do so anonymously here</a>.</p>
<p><strong><span style="color: #ff0000;">c</span>r</strong></p>
```


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## zim (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



Canon Rumors said:


> What our information doesn’t specify is whether or not it’s the identical sensor to the EOS 70D.</p>
> <p>If what we posted turns out not to be true, it will be the greatest hoax of specs that I have seen in the 6 years we’ve been around.



But it could still be 20.2 and be a new improved sensor (not identical), what you've posted still true and for you not to have been hoaxed though, no?


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## Canon1 (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*

The good news is that if it is a totally new sensor, it may be much better than the 70d and it will have better high ISO noise at 20.2 than 24 mp. Im all for a smaller sensor in aps-c. Truthfully, I wish it was closer to 12 or 16. We'd have a killer crop camera!


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## ajfotofilmagem (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



Canon1 said:


> The good news is that if it is a totally new sensor, it may be much better than the 70d and it will have better high ISO noise at 20.2 than 24 mp. Im all for a smaller sensor in aps-c. Truthfully, I wish it was closer to 12 or 16. We'd have a killer crop camera!


I'd be happier with a 16 megapixel sensor without dual pixel AF. Do not get me wrong. For the intended use of 7D Mark II (mini 1DX) the most important thing is a big improvement in noise above ISO 1600.


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## raptor3x (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



ajfotofilmagem said:


> Canon1 said:
> 
> 
> > The good news is that if it is a totally new sensor, it may be much better than the 70d and it will have better high ISO noise at 20.2 than 24 mp. Im all for a smaller sensor in aps-c. Truthfully, I wish it was closer to 12 or 16. We'd have a killer crop camera!
> ...



I don't know, I think dual pixel is really attractive if Canon implements that patent where dual pixel works in conjuction with the regular AF system. The most interesting thing about dual pixel AF (DPAF) is that it's precision scales with the maximum aperture of the lens whereas the regular phase detect system only offers a fixed precision based on the type of AF point used, though for a given aperture size traditional AF is supposedly more precise. This combined with the new feedback loop from the newer Canon lenses along with the ITR metering system from the 1DX propagating down to lesser bodies and I think AF is going be insanely good for the next generation of Canon bodies.


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## Chaitanya (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*

I will belive that a camera replacement for 7D exisits when canon will annnounce one. untill then its just a mythical camera used to shoot unicorns, snowman and the big foot.


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## pierlux (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



zim said:


> Canon Rumors said:
> 
> 
> > If what we posted turns out not to be true, it will be the greatest hoax of specs that I have seen in the 6 years we’ve been around.
> ...



I remember voices from past Canon Rumors claiming different prototypes were around, couldn't it be the leaked specs are a mix of several different "experiments"?...



Canon1 said:


> The good news is that if it is a totally new sensor, it may be much better than the 70d and it will have better high ISO noise at 20.2 than 24 mp. Im all for a smaller sensor in aps-c. Truthfully, I wish it was closer to 12 or 16. We'd have a killer crop camera!



Partly agreed. As I said in Don Haines' poll thread, either a low res/good high ISO IQ old tech sensor, or a high res/supposedly better high ISO IQ new tech sensor would do for me. I put better high ISO IQ than the 7D on top of the specs in order of importance, otherwise to me it's 70D or 80D.


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## bseitz234 (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



Canon Rumors said:


> I will release what we have in our possession



So, someone sent you a pre-production sample?


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## zim (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



bseitz234 said:


> Canon Rumors said:
> 
> 
> > I will release what we have in our possession
> ...



Yip, there is a photo of it on the home page, hiding in plain sight all along 8)


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## bseitz234 (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



zim said:


> bseitz234 said:
> 
> 
> > Canon Rumors said:
> ...



And all this time we thought that was a photoshop job... :


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## Lee Jay (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



Canon Rumors said:


> What our information doesn’t specify is whether or not it’s the identical sensor to the EOS 70D.



From the other post, "The sensor does have new technology".

How can you stand by what you said and contradict it at the same time?


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## Canon Rumors Guy (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



Lee Jay said:


> Canon Rumors said:
> 
> 
> > What our information doesn’t specify is whether or not it’s the identical sensor to the EOS 70D.
> ...



I see what you're saying.

The new technology claim was because of the wording "fine detail" when describing the CMOS sensor. We then quickly learned that Canon has used that language with previous sensors such as the 5D Mark III and 70D. When we removed the "fine detail" point, I didn't update the rest of the post to reflect that.

I'm sorry for the confusion.


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## Don Haines (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



Canon Rumors said:


> Lee Jay said:
> 
> 
> > Canon Rumors said:
> ...


Please don't take this the wrong way... but I won't believe anything until there is an official announcement.

Canon is VERY! good at keeping things secret... remember DPAF? This was the defining feature of the 70D and there was zero warning it was coming.... I wouldn't even be surprised if Canon had some fake specs circulating around to see where any leaks were coming from... The only thing I am sure of is that the rumours will not be 100 percent accurate....


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## Lee Jay (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*

I still say it's possible that it's the 70D sensor and new technology (better performance) at the same time. This is because it's possible that DIGIC 6 will reduce read noise from the same sensor compared to DIGIC 5+ in the 70D.


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## Maui5150 (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*

Curious to see. IF it is a 24MP with better HIGH ISO and stellar AF AND around $2K or less, than I should be in. Really will have to wait and see the final specs, but really want better than 20MB, solid AF with a wider spread... and improved ISO (5d MKIII or better) than I will be fairly happy


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## neuroanatomist (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



Maui5150 said:


> ... and improved ISO (5d MKIII or better)



I do believe in Santa Claus. I do I do I do. And flying reindeer. And rainbow-pooping unicorns. Any of those are more likely to be real than an APS-C sensor that's as good or better than the 5DIII at high ISO. 

In a fight between physics and fantasy, my money is on physics. 8)


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## Don Haines (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



neuroanatomist said:


> Maui5150 said:
> 
> 
> > ... and improved ISO (5d MKIII or better)
> ...


and you loose!

I'll take the photo scanner from BladeRunner (it can zoom in and in and in and read things off of the reflection of something that was around a corner) over the best current sensor any day..... and the main screen on the enterprise beats any 4K display for sale at Best Buy


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## unfocused (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*

If it doesn't have flashing LED lights Canon is *******. 

http://photorumors.com/2014/08/27/pentax-k-s1-dslr-camera-with-fancy-led-lights-officially-announced/#more-60114


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## ajfotofilmagem (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



unfocused said:


> If it doesn't have flashing LED lights Canon is *******.
> 
> http://photorumors.com/2014/08/27/pentax-k-s1-dslr-camera-with-fancy-led-lights-officially-announced/#more-60114








Man, I do not know how I could shoot so many years without LED flashing:
Steal me, steal me, steal me, steal me.


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## Maui5150 (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



neuroanatomist said:


> Maui5150 said:
> 
> 
> > ... and improved ISO (5d MKIII or better)
> ...



You are so mean! 

Not like the 5D MKIII is really setting the bar too high. I notice a lot of noise above ISO 800)


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## PureClassA (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*

I still can't fathom how folks are demanding ISO performance that meets or exceeds any Full Frame level. Check back into reality or buy Full Frame. Only setting yourself up for guaranteed disappointment. Even Canon is not able to defy the properties of light and matter. :


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## cnardo (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*

But if Canon said: "Canon today announces DETAILS of it presence at Photokina 2014..." where are they ??????


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## Don Haines (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



neuroanatomist said:


> Maui5150 said:
> 
> 
> > ... and improved ISO (5d MKIII or better)
> ...


and Neuro moves his hand from left to right, saying "These aren't the droids sensors you're looking for"


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## Sporgon (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



unfocused said:


> If it doesn't have flashing LED lights Canon is *******.
> 
> http://photorumors.com/2014/08/27/pentax-k-s1-dslr-camera-with-fancy-led-lights-officially-announced/#more-60114



I see Pentax are making a feature of 'proper' glass pentaprism- brightest viewfinder etc. Those 'flappy' mirror hating dudes are just so off the pace. (anyway who ever heard an APS cameras mirror 'flap'. )

As for the LED light, what is there to say ? Watch the birdie will never be the same again. The Pentax 6x7 must be rolling in its grave. ( And that mirror did flap  ).


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## slclick (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*

I'm in the Noise Camp on this one. ISO is why I sold mine. I wouldn't be interested unless it was pretty 'clean' at 6400 and as good as the 5D3 at 1600


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## AcutancePhotography (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



Don Haines said:


> and you loose!



(facepalm) :


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## ekt8750 (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



ajfotofilmagem said:


> Canon1 said:
> 
> 
> > The good news is that if it is a totally new sensor, it may be much better than the 70d and it will have better high ISO noise at 20.2 than 24 mp. Im all for a smaller sensor in aps-c. Truthfully, I wish it was closer to 12 or 16. We'd have a killer crop camera!
> ...



Same here if it means larger pixels that let more light in. Just look at Canon's prosumer camcorders which work on that very concept.


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## Lee Jay (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



ekt8750 said:


> ajfotofilmagem said:
> 
> 
> > Canon1 said:
> ...



Saying bigger pixels let more light in is like saying cutting a 15 inch pizza into 6 slices instead of 8 gets you more pizza.


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## Maui5150 (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



PureClassA said:


> I still can't fathom how folks are demanding ISO performance that meets or exceeds any Full Frame level. Check back into reality or buy Full Frame. Only setting yourself up for guaranteed disappointment. Even Canon is not able to defy the properties of light and matter. :



One I own Full Frame and mainly full frame - 5D MK III and II and use a t4i for backup video 

Been less than impressed with ISO above 800 on the 5D MK III especially noise on faces when shooting natural light in studio. Granted the 1Dx would be a far better choice, but given it has been 5 years since the 7D, 3 years since the 1Dx and 2.5 since the 5D MK III, one would hope that Canon has made significant inroads in sensor technology, especially given what some of the competition is doing.

It would be nice to see Canon release a new "King of the Crop" followed up by a High MP beast, 1Dxs and 5D MK IV

1Dx and 5D MKIII were decent step ups, but in the world of "what have you done lately", Canon's pro level bodies have been fairly stagnant

All things being equal, FF should beat crop on noise, but would not mind seeing a generational jump where a crop comes close and then the next gen FF blows the doors off.


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## Marauder (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



ajfotofilmagem said:


> unfocused said:
> 
> 
> > If it doesn't have flashing LED lights Canon is *******.
> ...



"This LED body illumination gives a decorative illumination to the choice of distinctive body colors; furthering the look of the camera as a sophisticated digital device." HA! That's it. Not getting a 7D2 or any other Canon camera! Switching to the Pentax so I can hypnotize birds with flashing LED's so they stay still!! I won't EVER buy a Canon again until they implement "operation Christmas Camera" on their models!!!!


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## NancyP (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*

Hey, I am going on a unicorn photo expedition in January, I need that slightly-better-than-70D high-ISO noise performance. 8)

Bigger pixels give more electron capacity per pixel (say, 4 micron pixel has 30,000 maximum capacity, 7 micro pixel has 100,000 maximum capacity). So, say you have 14-bit ADC, that's roughly 16,000 levels of electrons, or about 2 electrons per level for the 4 micron pixel and 6 electrons per level for the 7 micron pixel. Say you have 30 electrons worth of noise. Noise takes up the first 15 levels for the 4 micron pixel and the first 5 levels for the 7 micron pixel. That's why bigger pixels, all other things being equal, result in less perceptible noise.


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## Keith_Reeder (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



neuroanatomist said:


> In a fight between physics and fantasy, my money is on physics. 8)



Which ignores the fact that newer crop sensors are _waaay_ better in the high ISO noise stakes than old FF cameras.

There's more to this than "just" physics...


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## Keith_Reeder (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



NancyP said:


> That's why bigger pixels, all other things being equal, result in less perceptible noise.



At the pixel level - which is _irrelevant_ at the image level, because of the averaging effect of lots of smaller pixels - and their noise - across the image.

_Again_: even DxO gets this:
http://www.dxomark.com/Reviews/More-pixels-offset-noise


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## Lee Jay (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



NancyP said:


> Hey, I am going on a unicorn photo expedition in January, I need that slightly-better-than-70D high-ISO noise performance. 8)
> 
> Bigger pixels give more electron capacity per pixel (say, 4 micron pixel has 30,000 maximum capacity, 7 micro pixel has 100,000 maximum capacity). So, say you have 14-bit ADC, that's roughly 16,000 levels of electrons, or about 2 electrons per level for the 4 micron pixel and 6 electrons per level for the 7 micron pixel. Say you have 30 electrons worth of noise. Noise takes up the first 15 levels for the 4 micron pixel and the first 5 levels for the 7 micron pixel. That's why bigger pixels, all other things being equal, result in less perceptible noise.



Perceptible, perhaps, but it's also a smaller file. Reduce the large file to the smaller file's resolution, applying noise reduction as needed to keep the same final sharpness, and you'll usually find that the smaller pixels have less noise.


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## Keith_Reeder (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*

I don't know what the internet equivalent of sticking your fingers in your ears and going "la la la!" very loudly is called, but there's a helluva lot of it going on, on this site...

This "small pixels bad, big pixels good" tripe was beaten to death not long after the 7D was released: but here we are, 5 years later, reading the same Flat Earther "articles of faith"...

:


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## Mt Spokane Photography (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



cnardo said:


> But if Canon said: "Canon today announces DETAILS of it presence at Photokina 2014..." where are they ??????



Some people get confused by the hype easily. Its best to never buy anything based on written information if you try to read your own wishes into it. The article was describing the layout and operation Canon booth at the show, nothing else. 

New product announcements will be announced the week prior to the opening of the show. There may be prototypes at the show, or just large photo shopped images.

There will also be lots of brochures. They are printed in advance, and its likely that CR guy has a photo of one. He is not going to show it and risk outing the source. Canon extracts revenge on leakers. If a employee leaks something, the company he works for is punished.


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## x-vision (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



Lee Jay said:


> I still say it's possible that it's the 70D sensor and new technology (better performance) at the same time. This is because it's possible that DIGIC 6 will reduce read noise from the same sensor compared to DIGIC 5+ in the 70D.



The ISO range is reportedly the same as on the 70D, which doesn't bode well. 
I really hope that I'm wrong, though .


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## Lee Jay (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



x-vision said:


> Lee Jay said:
> 
> 
> > I still say it's possible that it's the 70D sensor and new technology (better performance) at the same time. This is because it's possible that DIGIC 6 will reduce read noise from the same sensor compared to DIGIC 5+ in the 70D.
> ...



Well, I wouldn't expect the approach I mentioned to provide a full 1-stop improvement so maybe it's just a little better but not enough for an expanded range.


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## crashpc (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*

Who knows. Remember, that this old 18Mpx sensor made it to lowest grade camera. Of course sensor is not what makes the whole camera, but if they end up with that old 20Mpx piece, It will be real ripoff, I´d be definitely done with Canon and painfully jumped elsewhere. That way I believe they will have something a little bit better, just not stellar. I´d be happy if it trupherd sensor of N D7100 or EOS 5D II, but I don´t believe it. Looking forward...


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## Maui5150 (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



NancyP said:


> Hey, I am going on a unicorn photo expedition in January, I need that slightly-better-than-70D high-ISO noise performance. 8)
> 
> Bigger pixels give more electron capacity per pixel (say, 4 micron pixel has 30,000 maximum capacity, 7 micro pixel has 100,000 maximum capacity). So, say you have 14-bit ADC, that's roughly 16,000 levels of electrons, or about 2 electrons per level for the 4 micron pixel and 6 electrons per level for the 7 micron pixel. Say you have 30 electrons worth of noise. Noise takes up the first 15 levels for the 4 micron pixel and the first 5 levels for the 7 micron pixel. That's why bigger pixels, all other things being equal, result in less perceptible noise.



Ummm... Where did I put the tylenol... I have a headache


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## jasonsim (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*

I bet it will be the same sensor as seen in the 70D. This would make sense, if Canon wanted to keep the price reasonable ( < $2k ). I would not be surprised if they price it at the same level of the previous 7D ( ~$1699). 

As far as much better high ISO performance, why would they do that? It would sabotage the sales of the flagship 1Dx. Lets get real...a crop sensor will never perform like a full frame. This should be the go-to camera for fair weather wildlife and sports photographers.

Just my two cents.


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## Lee Jay (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



jasonsim said:


> As far as much better high ISO performance, why would they do that?



Why wouldn't they, if they could? They've improved the performance of the crop sensors right along with the full frame sensors all along since the D30.


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## unfocused (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*

If this is what LED lights gets you, I think I'd rather have the LED lights after all. 

http://youtu.be/zva6-s8jza8


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## East Wind Photography (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*

My thoughts are that it will have wifi if the rumor is correct that it can sync time between 7dii cameras. Otherwise how could that be achieved and maintained? Also many of the gps chips now are combined with wifi..or vice versa...so from a capability standpoint this would not require much additional tech other than firmware.


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## roguewave (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



neuroanatomist said:


> I do believe in Santa Claus. I do I do I do. And flying reindeer. And rainbow-pooping unicorns. Any of those are more likely to be real than an APS-C sensor that's as good or better than the 5DIII at high ISO.
> 
> In a fight between physics and fantasy, my money is on physics. 8)



I don't disagree with you about sensors, but still, be careful betting all your money on it ...

"Heavier than air flying machines are impossible."
-- Lord Kelvin, president, Royal Society, 1895

"The resistance of air increases as the square of the speed and works as the cube [of speed].... It is clear that with our present devices there is no hope of aircraft competing for racing speed with either our locomotives or automobiles." 
-- William H. Pickering, Director, Harvard College Observatory, 1910

"Even considering the improvements possible...the gas turbine could hardly be considered a feasible application to airplanes because of the difficulties of complying with the stringent weight requirements." 
-- U. S. National Academy Of Science, 1940

"Professor Goddard...does not know the relation of action to re-action, and the need to have something better than a vacuum against which to react....he only seems to lack the knowledge ladled out daily in high schools." 
-- 1920 New York Times editorial on Robert Goddard's rocket work.

"The energy produced by the breaking down of the atom is a very poor kind of thing. Anyone who expects a source of power from the transformations of these atoms is talking moonshine." 
-- Ernest Rutherford, 1930

"This foolish idea of shooting at the moon is an example of the absurd length to which vicious specialization will carry scientists. To escape the Earth's gravitation a projectile needs a velocity of 7 miles per second. The thermal energy at this speed is 15,180 calories [per gram]. Hence the proposition appears to be basically impossible"
-- A. W. Bickerton, 1926

"Fooling around with alternating currents is just a waste of time. Nobody will use it, ever." 
-- Thomas Edison


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## digitalride (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*

I'm sure this is posted every so often, but it bears repeating. For everyone hoping for a full stop improvement in noise performance in the next model of a camera, it is NEVER going to happen. Today's sensors capture very roughly 50% of the incoming photons. So if a sensor was theoretically perfect, sensors could be one stop better. That's the best they will EVER be, without switching from a bayer color pattern to a foveon-like sensor. ( In that case you could theoretically get over another stop of improvement IF you were still able to maintain the same efficiency. ) So even in another 2000 years with insane technological advances there is no way that cameras could ever be 3 stops better in raw noise performance. 

So even if a sensor manufacturer could get close to 100% efficiency now, they would be insane to sell it from a business standpoint. They could release a sensor with 60% efficiency and still be the best, and give customers small improvements for years to come.

Quantum effeciencies:
http://www.dpreview.com/forums/post/53054826

We have been spoiled over the past decade - there was a full stop of improvement between the 5D to the 5Diii, but it just can't continue on that pace without breaking the laws of physics.


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## Lee Jay (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



digitalride said:


> I'm sure this is posted every so often, but it bears repeating. For everyone hoping for a full stop improvement in noise performance in the next model of a camera, it is NEVER going to happen. Today's sensors capture very roughly 50% of the incoming photons. So if a sensor was theoretically perfect, sensors could be one stop better. That's the best they will EVER be, without switching from a bayer color pattern to a foveon-like sensor. ( In that case you could theoretically get over another stop of improvement IF you were still able to maintain the same efficiency. ) So even in another 2000 years with insane technological advances there is no way that cameras could ever be 3 stops better in raw noise performance.
> 
> So even if a sensor manufacturer could get close to 100% efficiency now, they would be insane to sell it from a business standpoint. They could release a sensor with 60% efficiency and still be the best, and give customers small improvements for years to come.
> 
> ...



Quantum efficiency isn't the only driver. Read noise can be a major factor as well. In some cases (some sensors, some ISO settings) driving read noise to zero could provide better than a 1-stop improvement. While QE at 100% is not possible, read noise at essentially zero is possible.


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## NancyP (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*

Thank you, Lee Jay. An image results from the whole train of electronics, not just the raw electrons-per-well (pixel) count.

Now, I am off on the tylenol hunt, and I will definitely need high ISO for this - in case it lurks under the bed or at the back of the cabinet.


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## Sabaki (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*

Right now, in this moment in time, the biggest feature I'm looking for in the 7DX would be the ability to put an stop to this endless waffle about who knows what better when it comes to sensors, DR and noise. 

I respect everybody and their level of knowledge but damn! 

Sabaki's #1 7DX Feature?
A (full) stop to all this one uppance!


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## keithcooper (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*

FWIW ... I have to say I agree with the current CR 7D replacement specs - I've not seen any convincing info of late, indicating otherwise.

First time in a while that I'd be happy putting a [modest] bet on some specs ;-)

I guess we'll get further versions of that 20.2 MP sensor appear in the next crop DSLRs next year... but without the souped up AF of the 7D replacement (but I suppose that they will have touch screens and WiFi)


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## digitalride (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



Lee Jay said:


> Quantum efficiency isn't the only driver. Read noise can be a major factor as well. In some cases (some sensors, some ISO settings) driving read noise to zero could provide better than a 1-stop improvement. While QE at 100% is not possible, read noise at essentially zero is possible.



Yes, I hadn't considered lowering the read noise. Anyone know how many stops of noise improvement is practically and theoretically possible there? I don't know enough to make sense of the info at http://www.sensorgen.info . I want to get a number so I can spout off and say "noise performance cannot ever improve more than X stops from what we have today" every time someone expects a 2x improvement in the next model.


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## RGomezPhotos (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*

24MP at 10fps could be a reality with dual DIGIC 6 processors. And I can see them doing it for sports and wildlife photographers who regularly crop their images. I got a feeling it's going to set the standard for APS-C cameras if most of the rumors specs are true. I think Canon has to make it great to replace the still amazing 7D...


----------



## neuroanatomist (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



roguewave said:


> neuroanatomist said:
> 
> 
> > I do believe in Santa Claus. I do I do I do. And flying reindeer. And rainbow-pooping unicorns. Any of those are more likely to be real than an APS-C sensor that's as good or better than the 5DIII at high ISO.
> ...



Fair enough. But to clarify, my meaning was an APS-C sensor _announced by Canon at Photokina this year_ that's as good or better than the 5DIII at high ISO.


----------



## neuroanatomist (Aug 28, 2014)

*Re: EOS 7D Mark II & Photokina*



Keith_Reeder said:


> neuroanatomist said:
> 
> 
> > In a fight between physics and fantasy, my money is on physics. 8)
> ...





Keith_Reeder said:


> even DxO gets this:



Yes, even DxO gets how far we've come, that a new APS-C sensor like that in the 70D is _waaay_ better in terms of high ISO noise than an old FF sensor like that in the original 5D.

: : :


----------



## Lee Jay (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



digitalride said:


> Lee Jay said:
> 
> 
> > Quantum efficiency isn't the only driver. Read noise can be a major factor as well. In some cases (some sensors, some ISO settings) driving read noise to zero could provide better than a 1-stop improvement. While QE at 100% is not possible, read noise at essentially zero is possible.
> ...



Unlike shot noise, read noise's impact can't be quantified this way. At some ISOs and portions of the tone curve, it's negligible, at others, it's crucial.


----------



## jrista (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Lee Jay said:


> ekt8750 said:
> 
> 
> > ajfotofilmagem said:
> ...



HAHA! That's a PERFECT analogy!  Sweet. Gotta use that one in the future.


----------



## jrista (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



NancyP said:


> Hey, I am going on a unicorn photo expedition in January, I need that slightly-better-than-70D high-ISO noise performance. 8)
> 
> Bigger pixels give more electron capacity per pixel (say, 4 micron pixel has 30,000 maximum capacity, 7 micro pixel has 100,000 maximum capacity). So, say you have 14-bit ADC, that's roughly 16,000 levels of electrons, or about 2 electrons per level for the 4 micron pixel and 6 electrons per level for the 7 micron pixel. Say you have 30 electrons worth of noise. Noise takes up the first 15 levels for the 4 micron pixel and the first 5 levels for the 7 micron pixel. That's why bigger pixels, all other things being equal, result in less perceptible noise.



This is still wrong. Bigger pixels mean more charge per pixel...but it's still the same TOTAL CHARGE for the WHOLE SENSOR!  As Lee Jay said, slicing up a pizza into smaller slices doesn't mean you have more pizza, or more pepperoni on that pizza. It's still the same amount of food. 

Same for sensors. You can have two APS-C sensors with 10µm and 5µm pixels. One has four times as many pixels as the other. The sensors are 22.3x14.9mm in size. The big pixel sensor is 2230x1490 pixels, the small pixel sensor is 4460x2980 pixels. One has pixels with four times the area as the other. The 10µm pixels gather 100ke- charge FWC, the 5µm pixels gather 25ke- charge FWC. The bigger pixels are better, right? They gather more light than smaller pixels. They mean less noise, right? Nope. Let's calculate the total charge in the sensor for a fully saturated sensor

(2230*1490) * 100000 = 332,270,000,000e-
(4460*2980) * 25000 = 332,270,000,000e-

Hmm. Something MUST be wrong, because these two sensors gathered the same amount of light! If your subject fills the same absolute area of the sensor, then either sensor is going to gather the same total amount of light. The only difference is that one divides the subject into smaller buckets. _Each bucket gets less light_, *but the subject as a whole is resolved at the sensor with the exact same amount of light in total.* 

Oh, but I purposely used pixels that had a nice, neat little ratio between them. It doesn't work that way in real life, right? Let's prove the point. Let's take the 5D III and 6D, both full frame sensors. Their total charge capacities are:

5D III: (5760px*3840px) * 67531e-/px = 1,493,677,670,400e-
6D: (5472px*3648px) * 76606e-/px = 1,529,197,940,736e-

The 5D III has 49% Q.E., the 6D has 50% Q.E. Dividing the above by 49% and 50% respectively gives us:

1,493,677,670,400/49 = 30,483,217,763.27
1,529,197,940,736/50 = 30,583,958,814.72

Dividing those numbers gives us:

30,483,217,763.27/30,583,958,814.72 = 0.99670608203273169699921873489352

The 5D III and 6D are within 99.7% of each other as far as total charge goes. That means the difference in light gathering capacity is 0.3%..._well _within margin of error. Differences in technology, cherry picking the best sensors (as in the 1D X/D4 lines), using better companion electronics (again as in 1D X/D4), etc. can create larger discrepancies, but in general, differences in pixel size, until were talking about very small pixels where fill factor becomes an issue, are largely meaningless. It's sensor area that matters first and foremost, then quantum efficiency...then pixel size/fill factor. 

The 7D II could employ some new technology to improve Q.E. They could use better materials (i.e. black silicon), control current better, maybe even switch from using a standard RGGB CFA to using something like color splitting, etc. and maybe double Q.E. That would allow them to realize a REAL one-stop improvement in noise performance at high ISO. I think it's doubtful that's happened...if the 20.2mp sensor rumor is true. In all likelihood, Canon has made some minor evolutionary improvements, maybe improved Q.E. a few percent, maybe found a way to recover some die area for photodiodes, improved the efficiency of their circuitry, etc. I don't expect the differences to be huge. 

The 70D has 45% Q.E. The 7D II might have around 49% Q.E., and they may better utilize the sensor die area for photodiodes. We might see a boost from ~26ke- FWC to maybe ~30ke- FWC. That is not going to change things much...and accounting for the differences in quantum efficiency, the two sensors are still going to come within a fraction of a percent of each other as far as total light gathering capacity goes.


----------



## jrista (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



digitalride said:


> I'm sure this is posted every so often, but it bears repeating. For everyone hoping for a full stop improvement in noise performance in the next model of a camera, it is NEVER going to happen. Today's sensors capture very roughly 50% of the incoming photons. So if a sensor was theoretically perfect, sensors could be one stop better. That's the best they will EVER be, without switching from a bayer color pattern to a foveon-like sensor. ( In that case you could theoretically get over another stop of improvement IF you were still able to maintain the same efficiency. ) So even in another 2000 years with insane technological advances there is no way that cameras could ever be 3 stops better in raw noise performance.
> 
> So even if a sensor manufacturer could get close to 100% efficiency now, they would be insane to sell it from a business standpoint. They could release a sensor with 60% efficiency and still be the best, and give customers small improvements for years to come.
> 
> ...



Agreed. There are limits to how much we can improve high ISO performance....so long as we keep doing things the same way. 

There have been some intriguing innovations for video, where you might be able to use prior frame data to augment subsequent frame data (especially in high speed video), multi-bucket pixels, etc. I'm not sure how many of those innovations could be used for still photography. High ISO is physics limited, and for still frames at high ISO, the most common use case is to support a faster shutter speed. The use of technology like Aptina's multi-bucket high DR pixels probably wouldn't do much to improve total light gathered at high ISO (although it might be able to improve DR and eliminate signal clipping.)


----------



## sfunglee (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*

Well I'm going to get a new 7D2 a beefy juicy pizza...


----------



## sfunglee (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



jrista said:


> Lee Jay said:
> 
> 
> > ekt8750 said:
> ...



By logically 15" pizza are larger by 6 slices, but the 15" pizza thicker pizza into 8 slices will be different...
In another word, weight per pizza of 1/8 is heavier than 1/6... hrmmm it mean a possible for crop 24mp excel FF 21mp in term of more fine pixel? Sorry i'm no too good into pixel stuffs


----------



## Woody (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



x-vision said:


> The ISO range is reportedly the same as on the 70D, which doesn't bode well.
> I really hope that I'm wrong, though .



100% in agreement.


----------



## jrista (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



sfunglee said:


> jrista said:
> 
> 
> > Lee Jay said:
> ...



I'm not really sure what your trying to say. A pizza is a pizza. If it's 15" in diameter, it's ~177" in area. If you slice it up into six slices, each slice is 29.5" in area. If you slice it up into eight slices, each slice is 22" in area. However, if you eat all six larger slices, or eat all eight smaller slices, you still ate 177" total area worth of "pizza." Larger slices don't mean you get more pizza...it's still the same total amount of food regardless of how small you slice it!


----------



## neuroanatomist (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*

Now I'm hungry. ;D


----------



## Don Haines (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



neuroanatomist said:


> Now I'm hungry. ;D


Not me.... I just ate a plate of spaghetti so that when the sensor talk got all the way down to string theory, I would be ready....


----------



## weixing (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



jrista said:


> NancyP said:
> 
> 
> > Hey, I am going on a unicorn photo expedition in January, I need that slightly-better-than-70D high-ISO noise performance. 8)
> ...


Hi,
Err... I think you forget to consider the noise factor... if the noise for every pixel is the same, the larger pixel (more signal) will have better Signal-to-Noise ratio... that's mean more pixels equal more noise and since the total signal for the both sensor is the same, the sensor with less pixels will have better Signal-to-Noise ratio. Also, since smaller pixels hold less charge, the chance of blowing highlights is higher than a larger pixel sensor.

As a result, sensors with larger pixel have better dynamic range than sensors with smaller pixel even if the total sensor size is the same.

Have a nice day.


----------



## jrista (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



weixing said:


> Hi,
> Err... I think you forget to consider the noise factor... if the noise for every pixel is the same, the larger pixel (more signal) will have better Signal-to-Noise ratio... that's mean more pixels equal more noise and since the total signal for the both sensor is the same, the sensor with less pixels will have better Signal-to-Noise ratio. Also, since smaller pixels hold less charge, the chance of blowing highlights is higher than a larger pixel sensor, so larger pixel sensor will have a better dynamic range.
> 
> Have a nice day.



Nope. I haven't forgotten noise or SNR. The 5µm pixels will have twice the noise. However, a 2x2 matrix of 5µm pixels equal one 10µm pixel in terms of area. Average those four pixels together, and you reduce noise by SQRT(4), which is? Yup. A factor of two. The 10µm pixels have four times the area, which again, reduces noise by SQRT(4), or a factor of two. There is more noise per pixel, however the noise per absolute area of the subject is the same. The sensor with smaller pixels has twice the image dimensions. Downsample the 4460x2980 pixel image to 2230x1490...and there will be no difference in noise. 

The only difference you WILL see? The downsampled image is SHARPER! 8)

Have a nice day.


----------



## dtaylor (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Jaydeep said:


> When was the last time that we had two sensors having the exact same MP resolution but were "different " ?
> I'm afraid it looks like the 7D II will have the 70D sensor . The 70D sensor is pretty good though, its just that we are expecting two sensor revolutions in two years ..which is incredibly rare.



I realize if it has the 70D sensor that this will disappoint many. But if they keep the price down I'm fine with it. The 70D is a clear improvement in noise/DR over the original 7D, and 65 cross AF points at 10 fps is awesome. I don't think they can coast 5 years on this sensor, but as long as they don't price it into the stratosphere there is nothing that can touch it for action and sports right now outside of the top end 1DX / D4.

Now if they try to charge an arm and a leg for it, I'll just stick to my current 7D for sports/action. If they want to charge more then $2k (street price...we all know MRP is artificially high) then they have to have something "revolutionary" IMHO. Those rumors have been squashed. So we'll see what the price ends up being.


----------



## sarangiman (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



weixing said:


> Also, since smaller pixels hold less charge, the chance of blowing highlights is higher than a larger pixel sensor.



But for the same focal plane exposure, the smaller pixels also receive less light because, well, they're smaller. So total sensor DR does not necessarily have to suffer for higher resolution sensors. 



weixing said:


> As a result, sensors with larger pixel have better dynamic range than sensors with smaller pixel even if the total sensor size is the same.



If all else is held the same, yes. In reality, this doesn't generally always turn out to be true. For one, sometimes manufacturers are able to decrease per-pixel read noise with the smaller pixels of the higher resolution (but same size) sensor. For a sensor of _n_ times higher resolution, all you have to do is decrease per-pixel read noise by a factor of sqrt(_n_) to achieve equivalent _normalized_ noise performance. 

This may be why the Sony A7R has just as much DR as the A7S, and normalized noise performance is similar. But, admittedly, I'm just guessing here.

The point is, there are a number of variables here one must consider. It's not always straightforward. For example, the A7S with its 12MP has demonstrably lower DR in RAW than the A7R with 3x as many pixels. Probably resulting from increased downstream read noise of the architecture.



jrista said:


> Nope. I haven't forgotten noise or SNR. The 5µm pixels will have twice the noise. However, a 2x2 matrix of 5µm pixels equal one 10µm pixel in terms of area. Average those four pixels together, and you reduce noise by SQRT(4), which is? Yup. A factor of two. The 10µm pixels have four times the area, which again, reduces noise by SQRT(4), or a factor of two. There is more noise per pixel, however the noise per absolute area of the subject is the same. The sensor with smaller pixels has twice the image dimensions. Downsample the 4460x2980 pixel image to 2230x1490...and there will be no difference in noise.
> 
> The only difference you WILL see? The downsampled image is SHARPER! 8)
> 
> Have a nice day.



No, jrista, the noise per absolute area is *not* the same. It's pretty close, but it's still worse. It'll only be the same if the _n_-times higher resolution sensor has its pixel-level read noise reduced by a factor of sqrt(_n_) compared to the lower resolution sensor. Let's take the case of a 10µm x 10µm pixel, vs. this pixel divided up into four 5µm x 5µm pixels. Let's do some math:

For a 10µm pixel that receives 200 photons, QE=50%:

Signal = 100 (50% of 200 = 100 electrons)
Read noise=2
Shot noise = sqrt(100) = 10
Total noise = sqrt (10^2 + 2^2) = 10.198 [yes, this is an approximation, but it'll suffice]
Per-pixel SNR = 100/10.198 = 9.806

For the four 5µm pixels that also receive a total of 200 photons, or 50 photons each, QE=50%:

Signal = 25 (50% of 50 = 25 electrons)
Read noise = 2
Shot noise = sqrt(25) = 5
Total noise = sqrt (5^2 + 2^2) = 5.385
Per-pixel SNR = 25/5.385 = 4.6424
After averaging those 4 pixels, SNR increases by sqrt(4)=2, so SNR for that area is now 9.285
Another way of determining the SNR of the four averaged pixels is to calculate out the noise: total noise after averaging will be sqrt(4*sqrt(29)^2) = sqrt(116) which you can already tell is going to be more than sqrt(104), the total noise of the 10µm pixel. But let's continue: sqrt(116) = 10.77. Adding together the signal of the 4 pixels gives you a signal of 100. So SNR = 100/10.77 = 9.285.

Point is, SNR of 9.8 > SNR of 9.3. This is generally a bit academic of a difference, which is why high resolution sensors generally do so well. But for extremely high ISOs, where you have so little signal to begin with, it can make a difference. Or when the higher resolution sensor has many, many more pixels.

The take-home point is that when you average the smaller pixels of a _n_-times higher resolution sensor, you completely equalize shot-noise performance _per-area_. But not read noise performance. Why? Simply b/c you have _n_ times as many read events.


----------



## LetTheRightLensIn (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Canon1 said:


> The good news is that if it is a totally new sensor, it may be much better than the 70d and it will have better high ISO noise at 20.2 than 24 mp. Im all for a smaller sensor in aps-c. Truthfully, I wish it was closer to 12 or 16. We'd have a killer crop camera!



How? If it is 12MP then it's getting to be not the ton more reach than a 5D3 is. It's not the crop factor that matters, it's the photosite density. All teh crop factor does is limit your FOV with each lens.


----------



## LetTheRightLensIn (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



raptor3x said:


> ajfotofilmagem said:
> 
> 
> > Canon1 said:
> ...



If they really did manage to pull of one the rumors where they claim it does DPAF so quickly that it after phase AF it can do quick final DPAF check and adjustment so fast that it wouldn't hurt reaction time (which seems hard to believe), but if they could, man it would have the best AF bar none and it would be an AF revolution.


----------



## LetTheRightLensIn (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Maui5150 said:


> and improved ISO (5d MKIII or better) than I will be fairly happy



That is really asking a lot, to do that it would basically have to be very nearly the 100% ideal sensor to simply match the 5D3 for SNR. It's a totally unrealistic ask. If you mean for DR then sure, it could do 3 stops better low ISO and 1.5 high ISO than the 5D3 for sure, but for SNR you are just not asking something it is remotely realistic.

You have to understand how crazy good the SNR of the current top cams are at high iso already. There isn't all that much room left to improve without breaking very basic laws of physics.


----------



## LetTheRightLensIn (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Lee Jay said:


> ekt8750 said:
> 
> 
> > ajfotofilmagem said:
> ...



It does if you were told "don't eat more than two slices!!!!" ;D.


----------



## LetTheRightLensIn (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Keith_Reeder said:


> neuroanatomist said:
> 
> 
> > In a fight between physics and fantasy, my money is on physics. 8)
> ...



Really, so these new APS-C cams are doing like like say capturing more photons than exist in a scene???


----------



## LetTheRightLensIn (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Keith_Reeder said:


> NancyP said:
> 
> 
> > That's why bigger pixels, all other things being equal, result in less perceptible noise.
> ...



At extremes of pixel size it can matter a bit for SNR. For lots of tech if you go wayyyyyyy high and compare to vastly lower you can get a bit of an actual penalty with the tech Canon is using now, but for anything like say 12MP vs 24MP I mean it's not even worth thinking about (and the more MP can even maybe help the DR a trace, plus the more MP the tighter the 'grain' which pleases the eye more which would make up for more than any little difference). So you might get a bit better DR and a bit worse SNR for typical modern tech and the way it works out, but for it to matter to the point you'd really care, especially for SNR you need quite a difference.


----------



## LetTheRightLensIn (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



roguewave said:


> neuroanatomist said:
> 
> 
> > I do believe in Santa Claus. I do I do I do. And flying reindeer. And rainbow-pooping unicorns. Any of those are more likely to be real than an APS-C sensor that's as good or better than the 5DIII at high ISO.
> ...



so?

lots of those of those quotes are simply about not imagining better tech, which is far different than going up against limits of basic physics and some are ridiculously flat out misinterpretations of basic physics that were well known by anyone who actually knew physics then


----------



## LetTheRightLensIn (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



digitalride said:


> Lee Jay said:
> 
> 
> > Quantum efficiency isn't the only driver. Read noise can be a major factor as well. In some cases (some sensors, some ISO settings) driving read noise to zero could provide better than a 1-stop improvement. While QE at 100% is not possible, read noise at essentially zero is possible.
> ...



I think the 6D is already something like at leat 2 stops better DR at high ISO than the 7D and Exmor is like 3 stops so certainly at least 3 stops low ISO and 2 stops high ISO without even having to do anything revolutionary.


----------



## LetTheRightLensIn (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



neuroanatomist said:


> Keith_Reeder said:
> 
> 
> > neuroanatomist said:
> ...



you really should compare using the normalized chart:
http://www.dxomark.com/Cameras/Compare/Side-by-side/Canon-EOS-70D-versus-Canon-EOS-5D___895_176

that said it still doesn't quite match the 5D, much less outdo it


----------



## LetTheRightLensIn (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Don Haines said:


> neuroanatomist said:
> 
> 
> > Now I'm hungry. ;D
> ...



oh no!!!! you ate the strings!!!!!!!


----------



## dufflover (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*

Add me to the list of people hoping it's a 24MP - not because I want that number (though it would be a nice bump!) but because of 20.2 indicating it's a derivative of the 70D sensor. I really like using my 70D but it's the big jump in sensor tech I want Canon to do and even if you aren't directly interested in the 7D II at least it shows what they have done will feature in future bodies.


----------



## serendipidy (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*

The problem with the basic laws of physics is that our understanding of them has always been incomplete. They still are.


----------



## dtaylor (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



LetTheRightLensIn said:


> you really should compare using the normalized chart:
> http://www.dxomark.com/Cameras/Compare/Side-by-side/Canon-EOS-70D-versus-Canon-EOS-5D___895_176
> 
> that said it still doesn't quite match the 5D, much less outdo it



* Open Comparometer.
* Compare old 5D and modern 70D.
* DxO is *wrong again.* :

Serious question: does anyone at DxO even own a camera?

That said, I wouldn't expect crop sensors to match today's FF sensors on noise for another few years, at which point FF will be that much better. For a given level of tech the larger sensor simply gathers more light. I seriously doubt that the 7D2 sensor will make some kind of leap to FF high ISO, and if it does then the 5D4 won't be far behind with the same tech and even better high ISO.

That doesn't mean crop is a slouch at high ISO though. Its gotten pretty good.


----------



## Canon1 (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



LetTheRightLensIn said:


> Canon1 said:
> 
> 
> > The good news is that if it is a totally new sensor, it may be much better than the 70d and it will have better high ISO noise at 20.2 than 24 mp. Im all for a smaller sensor in aps-c. Truthfully, I wish it was closer to 12 or 16. We'd have a killer crop camera!
> ...



A 12mp sensor would have better high ISO performance, utilize the center of lens elements, pair that with 10fps and I think that would be a great crop camera package. Better in the field then a 5d3 or a 1div. Of which I have both. 

And also, a 12 mp crop sensor is 150% of the "reach" and 16mp is 200% of the "reach"... As you put it.

Just my ideal wildlife camera.


----------



## Lee Jay (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Canon1 said:


> A 12mp sensor would have better high ISO performance,



No, it wouldn't. This myth just won't go away.



> utilize the center of lens elements,



Which is wrong on two levels - every pixel uses all of the lens elements. You may have meant "image circle" instead of lens elements. Secondly, using the "sweet spot" is nearly always detrimental compared to using the entire image circle because of increased enlargement.



> And also, a 12 mp crop sensor is 150% of the "reach" and 16mp is 200% of the "reach"... As you put it.



"Reach" means "resolving power" and it goes with the square of pixel count. You want to double resolving power? You need four times as many pixels.


----------



## Canon1 (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Lee Jay said:


> Canon1 said:
> 
> 
> > A 12mp sensor would have better high ISO performance,
> ...



Whatever... my opinions are derived from "field" observation... and interestingly I have found that most things being equal, larger pixels translate to higher ISO noise usability.... and that the center of images are always sharper and have less distortion than the edges. But who needs field observations when we have all of these "theoretical" photographers here on the forum to prove us all wrong??


----------



## Lee Jay (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Canon1 said:


> Lee Jay said:
> 
> 
> > Canon1 said:
> ...



I've got a quarter million shots under management in LR. I wouldn't call that theoretical.

You're noise observation is wrong because you are comparing at different enlargement ratios (1:1 with all pixel counts).

Your center image circle is wrong because you aren't comparing crops and full image circle images at constant final size.

And what I said about "reach" (resolving power) is correct.


----------



## sanj (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Canon1 said:


> Lee Jay said:
> 
> 
> > Canon1 said:
> ...



"whatever"! Really? Some facts thrown your way and you disregard it….


----------



## Famateur (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Jaydeep said:


> When was the last time that we had two sensors having the exact same MP resolution but were "different " ?
> I'm afraid it looks like the 7D II will have the 70D sensor . The 70D sensor is pretty good though, its just that we are expecting two sensor revolutions in two years ..which is incredibly rare.



Agreed. I know everyone (including me) hopes that the 7DX will have some jaw-dropping sensor tech, but the 7D and 60D shared the same 18MP sensor. The differentiation that justified the price difference was AF system, FPS, buffer depth, weather sealing and build quality.

Why should we expect the next generation of each camera to have a different relationship to one another? It would be unusual for Canon to make a "successor" to the 7D that was positioned differently in the market. Not saying it can't happen -- just saying it seems most likely that the positioning of the two products in relation to one another continues.

The 7DX uses the same sensor as the 70D and continues the differentiation with beefy AF system, FPS, buffer depth and even more solid build. Seems predictable to me. Of course, it's the predictability that gets so many shorts in a twist on this forum... :-X


----------



## Famateur (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*

Dare I wade into the pizza war? 

Perhaps I can translate it into a wooden pizza to fit one of my other hobbies: If I have a 15" maple disc, cutting it into 6 pieces WOULD give me more maple surface area than cutting it into 8 pieces. Why? because there is waste from blade kerf. If I have a 1/8" kerf, I lose an approximately 1/8" slice of material with each cut. Let's say now that we fill in each cut with a 1/8" slice of ebony so we don't lose _overall _surface area when we glue it all up. The disc maintains its original surface area, but there is still less maple surface area with 8 slices than with 6. Using a 1/16" kerf blade will increase the ratio of maple surface area to ebony, but there will still be less maple surface area with 8 slices than with 6.

Now imagine the disc is actually a rectangle, and the pieces are squares instead of pizza slices. The maple is the photo-sensitive portion of the sensor, and the ebony is the border around each pixel. If sensor size and transistor size are constant, doesn't increasing the number of pixels increase the number of borders and transistors, and doesn't that reduce the portion of the overall sensor that receives light? Is moving from a 500nm process to a 180nm process like going from a 1/8" kerf to 9/200" kerf?

I'm obviously not a sensor geek, so I might be completely misunderstanding pixels, borders, et cetera. What am I missing in this analogy?


----------



## nebugeater (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Famateur said:


> Jaydeep said:
> 
> 
> > When was the last time that we had two sensors having the exact same MP resolution but were "different " ?
> ...




Your logic might be correct just maybe the relationship is wrong. What is to say the 7DII will not have the same sensor as the 80D


----------



## bseitz234 (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Famateur said:


> Jaydeep said:
> 
> 
> > When was the last time that we had two sensors having the exact same MP resolution but were "different " ?
> ...



Well, for one, the 7D came out before the 60D, and the sensor that was in the 7D trickled down the line. Not up to the 7D from the 60D. So, the real question is about the relationship between the 7D2 and the 80D, not the 70D.


----------



## Canon1 (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



sanj said:


> "whatever"! Really? Some facts thrown your way and you disregard it….



Oh... my bad. My observations in the field have been proven wrong (Thanks LeeJay!), and I have revised my "wish list" for a new 7D.

Sanj... I appreciate all the facts that are thrown around here. Just look at the 50+ page thread on the 7D started a few days ago. There are so many facts in there that prove every other fact wrong that nothing could possibly be true.

I'm not disregarding the facts, I'm just stating that my opinions for a great APS-C camera are based on my own field operation. Truthfully, I don't care about the physics. What I care about is generating high quality images and through my own experience, I believe that my "wish list" for a great APS-C camera help create cleaner more usable files at high ISO. I'm not about to debate what makes a pixel produce better noise. If canon can make a 24mp APS-C camera that produces excellent quality, low ISO noise at ISO 3200... I don't care what goes into it. In my experience, this would be a more realistic achievement if that crop sensor was 12 or 16MP.


----------



## Famateur (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



nebugeater said:


> Famateur said:
> 
> 
> > Jaydeep said:
> ...



Good point! Let's hope so!!!


----------



## Don Haines (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Famateur said:


> Dare I wade into the pizza war?
> 
> Perhaps I can translate it into a wooden pizza to fit one of my other hobbies: If I have a 15" maple disc, cutting it into 6 pieces WOULD give me more maple surface area than cutting it into 8 pieces. Why? because there is waste from blade kerf. If I have a 1/8" kerf, I lose an approximately 1/8" slice of material with each cut. Let's say now that we fill in each cut with a 1/8" slice of ebony so we don't lose _overall _surface area when we glue it all up. The disc maintains its original surface area, but there is still less maple surface area with 8 slices than with 6. Using a 1/16" kerf blade will increase the ratio of maple surface area to ebony, but there will still be less maple surface area with 8 slices than with 6.
> 
> ...


I would say that you have it correct and that your analogy is cutting edge


----------



## Famateur (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Don Haines said:


> Famateur said:
> 
> 
> > Dare I wade into the pizza war?
> ...



I _saw _what you did there. ;D

By the way, for your birthday next weekend, maybe the "big white" socks you get will have an "L" series red stripe and weather sealing for long canoe trips. 8)


----------



## Lee Jay (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Famateur said:


> Dare I wade into the pizza war?
> 
> Perhaps I can translate it into a wooden pizza to fit one of my other hobbies: If I have a 15" maple disc, cutting it into 6 pieces WOULD give me more maple surface area than cutting it into 8 pieces. Why? because there is waste from blade kerf. If I have a 1/8" kerf, I lose an approximately 1/8" slice of material with each cut. Let's say now that we fill in each cut with a 1/8" slice of ebony so we don't lose _overall _surface area when we glue it all up. The disc maintains its original surface area, but there is still less maple surface area with 8 slices than with 6. Using a 1/16" kerf blade will increase the ratio of maple surface area to ebony, but there will still be less maple surface area with 8 slices than with 6.
> 
> ...



What you're missing is gapless microlenses, which essentially render the "blade kerf" largely moot by concentrating the light into the light-sensitive area between the "kerf lines".


----------



## pierlux (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*

Sorry, it's a long post, maybe too long.

In physics, the Carnot cycle is an ideal representation of a perfect engine having 100% efficency. It is a useful thermodynamic representation to explain energy conversion. In the real world, such a system does not exist.

Too many of you claim that a higher MP sensor does not have more noise than a lower MP one, all conditions being equal, and support this claim with mathematics, but that's not true in the real world. Some even claim that smaller photosites have less noise than bigger ones: now, that's the kind of claim that should make all of us invoke Santa, bigfoot and rainbow-pooping unicorns going on vacation together with a flying saucer. The real world behaves differently.



Lee Jay said:


> Saying bigger pixels let more light in is like saying cutting a 15 inch pizza into 6 slices instead of 8 gets you more pizza.



No. Your logic is flawed. 

If the pizza represents the sensor, the number of slices correspond to the number of the pizza eaters, represented by the sensels, i.e. photosites, i.e. pixels. An eater who eats 1/6 of the pizza eats more than one eating 1/8 of it. An ideal 24 x 36 mm sensor being a single light sensitive unit is a one pixel sensor which, let's say, collects 1 billion photons at a given time unit and luminous intensity; it has the lowest resolution possible, but it would be capable of letting you know if even a bunch of photons have hit it or not with 100% certainty, i.e. with zero noise. Ideally, if you divide that single huge photosite into 1 million smaller photosites (1 MP sensor), each photosite receives IDEALLY 1000 photons under the same conditions; in the practice it's less than 1000 because of the wiring and the spacing between photosites which equally absorb the photons, but do not convert them into a useful signal, instead convert them into heat, which is detrimental. This 1 MP sensor has sufficient resolution to resolve enough detail for a very small print, and with today's tech you could probably use it at 204,800 ISO or more with very low noise (and before any of you reply that you can reduce the size of the image and therefore reduce noise and equally obtain the print, try exposing a 36 MP sensor at 204,800 ISO or higher if you can...).

Again, the same sensor with 20 MP exposed in the same conditions does not collect 50 photons per photosite, but MUCH LESS this time due to massive wiring and lots of wasted space between photosites, so you have a high resolution image, but with a lot of noise.

Actually, in my example with 1,000,000,000 total photons hitting a 24 x 36 mm sensor I think you'd have only random noise at 20 MP, but it was for the sake of explaining. I'm not talking quantum efficency at all here, it's just the number of photons you can effectively use I'm talking about. Moreover, we don't have a linear relationship between number of photons and noise, so it's not as if you have half of the photons per photosite you double the noise, the situation is worse in the real world.

The Canon 1Dx is 18 MP; in the Nikon D800, being 36 MP, each photosite collects LESS than one half of each of the Canon's photosites, that's why the 1Dx is much better in low light. And the D800 holds because of its superior sensor tech (let's face it, fortunately Canon's system is better as a whole), otherwise they wouldn't have made it 36 MP in the first place.

In the pizza analogy, the more you cut the pizza, the more breadcrumbs, morsels, atomies you produce, leaving the eaters with less and less pizza to eat to the point that, putting together all the slim slices of pizza eaten by all, they add up to not even a quarter of the original one. And, actually, a pie should be a better fitting analogy.

It's like having a 100 x 100 ft room all for yourself, 10,000 square feet is plenty of space. But if you want to accomodate 100 people inside it and offer them a bit of privacy, you have to build walls which eat space, not to mention furniture, so you end up with much less than 100 sq. ft for each dweller.

Still not convinced? OK, you may say "who are you to stand up and make such claims against my maths?", so let's look at what Canon's engineers have done, I bet they know more than me or anyone else on CR about silicon performance and noise. This is what I wrote in a previous post: 

"There's a reason the 1Dx has the best (to my eye) IQ of all the DSLRs available to date (yes, better than any Nikon I think): its 18 MP FF sensor. And there's a reason why Canon developed a prototype sensor with photosites 7.5 times larger than the 1Dx: to capture quality video in candlelight (candledrkness sounds better, though). Don't know if you remember, but check these:

http://www.canon.com/news/2013/mar04e.html

http://petapixel.com/2013/09/13/canon-debuts-exciting-prototype-sensor-exceptional-low-light-capability/

And Sony? Compare the the 36 MP Alpha A7r(esolution) and the 12 MP A7s(ensitivity), then say again that more MP does not mean more noise if you dare. At base ISO maybe, but try going at 800 and beyond...

And should somebody dare claim again that smaller photosites means less noise as I've read too many times, remember Santa & Co. are watching us from their flying saucer... And again, at base ISO maybe, but what's the point of shooting 36 MP and then reduce resolution in post to lower the noise and make small prints or web sized images?

I'm going to spend the weekend with my son, so I'll be having a look at CR every now and then, but I'm not going to post, sorry. Have a nice weekend you all, too!

Peace!


----------



## Lee Jay (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



pierlux said:


> Too many of you claim that a higher MP sensor does not have more noise than a lower MP one, all conditions being equal, and support this claim with mathematics, but that's not true in the real world. Some even claim that smaller photosites have less noise than bigger ones: now, that's the kind of claim that should make all of us invoke Santa, bigfoot and rainbow-pooping unicorns going on vacation together with a flying saucer. The real world behaves differently.



Oh, really. Same ISO, same f-stop, same shutter speed, same focal length, same subject, same lighting, shot in raw, same raw processing tool. The pixels on the left are 1/16th as big (in area) as the pixels on the right.


----------



## pierlux (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Lee Jay said:


> pierlux said:
> 
> 
> > Too many of you claim that a higher MP sensor does not have more noise than a lower MP one, all conditions being equal, and support this claim with mathematics, but that's not true in the real world. Some even claim that smaller photosites have less noise than bigger ones: now, that's the kind of claim that should make all of us invoke Santa, bigfoot and rainbow-pooping unicorns going on vacation together with a flying saucer. The real world behaves differently.
> ...



Which ISO? Which f-stop? Which sensors? Could you provide a link, please? I've found this 

http://photos.imageevent.com/sipphoto/samplepictures/Pixel%20density%20test%202%20detail%20filtered.jpg 

but I can't find the exif, nor a caption. Sorry, I'm not particularly smart with computers... help me. Thanks!


----------



## Lee Jay (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



pierlux said:


> Lee Jay said:
> 
> 
> > pierlux said:
> ...



ISO 800 (the highest setting available at the time on the small pixels. The cameras as the Canon S3IS and the Canon 5D.


----------



## pierlux (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Lee Jay said:


> pierlux said:
> 
> 
> > Lee Jay said:
> ...



So the 6 MP p&s S3IS has better IQ of the 13 MP full frame 5D? Could you provide a link please so that I can see all by myself without asking you more detail? Thanks. Sorry, but I'm going to board my car in 5 min, as I said I have to pick my son to spend the weekend with him. I promise you I'll publicly apologize if you convince me, but please Lee Jay, read all my post and tell me where my logic is flawed. See you tomorrow (or tonight, I'm on the other side of the world...)
Cheers!


----------



## Lee Jay (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



pierlux said:


> So the 6 MP p&s S3IS has better IQ of the 13 MP full frame 5D?



No, the 2.04 micron pixels of the S3IS provide better IQ behind the same lens as the 8.2 micron pixels of the 5D. In other words, small pixels win.



> Could you provide a link please so that I can see all by myself without asking you more detail? Thanks.



I don't know what link you want. They're my pictures.

The reason this works is pretty simple - the same amount of light falls on the same area of the sensor regardless of how you divide that sensor up into pixels. Lots of small ones or one large one, it's all the same light. The difference is, with the small ones, you can choose to reduced your resolution down to the same as you get from the large one (and reduce noise along with it), or not. You can't make that choice with the larger pixels. Further, when you reduce your resolution, you can choose to use far more effective techniques than the simple block-averaging approach that is effectively what the larger pixels are doing - averaging over the large block size of the large pixels.


----------



## Famateur (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Lee Jay said:


> Famateur said:
> 
> 
> > Dare I wade into the pizza war?
> ...



Interesting. So you're saying that the microlenses can redirect virtually all the light (that would have fallen on the border) into the photo site (or that if any is lost, the final result is not appreciably different)? Good to know.

So moving to a smaller process to shrink the borders does not affect the amount of light captured for each pixel because of the gapless microlenses? 

If microlens size = photo site + border, then it would seem that a larger pixel-with-microlens would gather more light than a smaller pixel-with-microlens. Are you saying that the resolution (given the same sensor dimensions) is higher for the smaller pixels so when you compress the image to the same resolution as the sensor with the larger (fewer) pixels, the overall light/data collected for the multiple smaller pixels, now sized-down to the lower resolution end up producing essentially the same image quality? Am I understanding this right? Does this mean that if I want to enjoy the same image quality as the sensor with fewer pixels I have to compress the resolution of my images to match?

One other thought: microlenses perfectly focusing the light on the photo site sounds great on paper. How precisely do the lenses do this in the real world? If they're nearly perfect, how in the world do they accomplish such precision on such a small scale? Simply amazing to me...

If the microlenses do their job, then I guess it's not light/surface-area that makes the difference between crop and full frame. Could it be that for the smaller pixels, there's more opportunity for noise to be introduced by the supporting circuitry? Something must be happening, because it seems that sensors with larger pixels seem to do better for noise at high ISO.

I'm obviously showing my ignorance here, and at the risk of inviting the sensor-tech-savvy among us to bury me in information over my head, but hey...why not?


----------



## Lee Jay (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Famateur said:


> So moving to a smaller process to shrink the borders does not affect the amount of light captured for each pixel because of the gapless microlenses?



Pretty much, yes.



> If microlens size = photo site + border, then it would seem that a larger pixel-with-microlens would gather more light than a smaller pixel-with-microlens. Are you saying that the resolution (given the same sensor dimensions) is higher for the smaller pixels so when you compress the image to the same resolution as the sensor with the larger (fewer) pixels, the overall light/data collected for the multiple smaller pixels, now sized-down to the lower resolution end up producing essentially the same image quality?



Yes, though if you do the down-sizing properly, the smaller pixels will generally win, and quite easily.



> Am I understanding this right? Does this mean that if I want to enjoy the same image quality as the sensor with fewer pixels I have to compress the resolution of my images to match?



That depends on what you mean by image quality. Resolution? Noise? With the smaller pixels, you have the option to reduce noise at the expense of resolution. On the larger pixels, that part has been done for you and you have no choice.



> One other thought: microlenses perfectly focusing the light on the photo site sounds great on paper. How precisely do the lenses do this in the real world? If they're nearly perfect, how in the world do they accomplish such precision on such a small scale? Simply amazing to me...



The efficiency varies with the design, but it's quite close to all of the light. They do this using the techniques of photolithography, which is quite a precise thing, especially in the more modern versions.



> If the microlenses do their job, then I guess it's not light/surface-area that makes the difference between crop and full frame. Could it be that for the smaller pixels, there's more opportunity for noise to be introduced by the supporting circuitry? Something must be happening, because it seems that sensors with larger pixels seem to do better for noise at high ISO.



They do this because they use more sensor area, not because they use larger pixels. When you have the same f-stop, the light intensity (called "illuminance" - light per unit of area) is the same (for a given scene), and that means a sensor with more area captures more light. Since signal-to-noise ratio goes with sqrt(total light captured), more area (bigger sensor) means better signal to noise ratio for the same f-stop. That's why larger sensor perform better in low light.

Another way to look at the same thing is to express f-stop as its definition - focal length / aperture. So, a lens with a 100mm focal length and a 25mm aperture has an f-stop of 4 (it's often written as its reciprocal - 1/4 or 1:4).

Well, let's say you want to use your 100/4 on your full-frame camera. To what do you compare? Well, on a 1.6-crop camera, you might use the same lens zoomed out to 62.5mm so that you have the same angle of view. 62.5mm / 4 = 15.625mm compared with 25mm on the full-frame camera. That's a lot smaller hole for the light to squeeze through, and so you get a lot less.

The two explanations are equivalent.


----------



## sarangiman (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



pierlux said:


> And Sony? Compare the the 36 MP Alpha A7r(esolution) and the 12 MP A7s(ensitivity), then say again that more MP does not mean more noise if you dare. At base ISO maybe, but try going at 800 and beyond...



I'll take your ISO 800 and beyond and raise you a comparison between the A7r and A7s at ISO 3200:

http://www.dpreview.com/reviews/image-comparison/fullscreen?attr65_0=sony_a7s&attr65_1=sony_a7r&attr66_0=3200&attr66_1=3200&attr67_0=raw&attr67_1=raw&attr68=12mp&normalization=full&widget=119&x=0.15845192244437983&y=0.31115156636410585.

See any difference between the two when normalized to 12MP? I don't think so. Everything was controlled in this test, down to using the same exact lens, same shutter speed, aperture, ISO, etc.

In fact, I don't see any appreciable advantage over the A7R until you hit ISOs of 25.6k and beyond. Because at that point, the crumbs start encroaching on the slices, in the pizza analogy. For deep deep shadows, the A7S' takes over at ISOs of 6400 and beyond. Really depends on the tone you're looking at, b/c different tones are affected differently by the different sources of noise (shot noise, read noise, etc.).

But ISO 800? 1600? You're unlikely to see any appreciable difference.

LTRLI also made an interesting point about finer-grained noise of higher resolution sensors. So there's also that to consider.


----------



## jrista (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*

You've made a lot of logical mistakes, so I'll address them one by one below. 



pierlux said:


> Sorry, it's a long post, maybe too long.
> 
> In physics, the Carnot cycle is an ideal representation of a perfect engine having 100% efficency. It is a useful thermodynamic representation to explain energy conversion. In the real world, such a system does not exist.
> 
> Too many of you claim that a higher MP sensor does not have more noise than a lower MP one, all conditions being equal, and support this claim with mathematics, but that's not true in the real world. Some even claim that smaller photosites have less noise than bigger ones: now, that's the kind of claim that should make all of us invoke Santa, bigfoot and rainbow-pooping unicorns going on vacation together with a flying saucer. The real world behaves differently.



I would say the exact same thing about the notion that bigger pixels gather enough "more light" to be meaningful given how sensors are designed today. Your missing how all the small changes to sensor design have largely nullified and negated the impact of *fill factor*. Fill factor is the ratio of sensor die space dedicated to light sensitive area vs. non-sensitive area (i.e. wiring, transistors, etc.) 



pierlux said:


> Lee Jay said:
> 
> 
> > Saying bigger pixels let more light in is like saying cutting a 15 inch pizza into 6 slices instead of 8 gets you more pizza.
> ...



Nope, his logic is actually *flawless*, and here is why:



pierlux said:


> If the pizza represents the sensor, the number of slices correspond to the number of the pizza eaters, represented by the sensels, i.e. photosites, i.e. pixels. An eater who eats 1/6 of the pizza eats more than one eating 1/8 of it.



Your only thinking about the individual pizza slices here. Your missing the bigger picture: The eater who eats 1/6th of a pizza eats 1/6th of a pizza SIX TIMES!! Therefor, the eater is not eating one pizza slice...*the eater is eating A WHOLE PIZZA!* ;D _This is the critical point that everyone seems to miss._ If an eater eats two 15" pizzas, one cut into 6ths and one cut into 8ths...has the eater eaten less total pizza when eating the one cut into 8ths? NOPE!! He's still eaten a whole 15" pizza, same as he did when he ate the one cut into 6ths. 

We don't generally use image sensors in slices. We frame our scene and we take a photo. Ignoring cropping for the moment, our sensor, the ENTIRE sensor, regardless of how many pixels it has, was used to create an image. Now, cropping does play a factor. If we crop, we are using less area, and throwing away some of the sensor area. That might be like eating two or three slices of pizza, instead of a whole entire pizza. However, what role does pixel size play? I mean, if we have one pizza cut into 6 slices, and another pizza cut into 12 slices...if we eat two of one or four of the other, we've still eaten the same amount of pizza.



pierlux said:


> An ideal 24 x 36 mm sensor being a single light sensitive unit is a one pixel sensor which, let's say, collects 1 billion photons at a given time unit and luminous intensity; it has the lowest resolution possible, but it would be capable of letting you know if even a bunch of photons have hit it or not with 100% certainty, i.e. with zero noise. Ideally, if you divide that single huge photosite into 1 million smaller photosites (1 MP sensor), each photosite receives IDEALLY 1000 photons under the same conditions; in the practice it's less than 1000 because of the wiring and the spacing between photosites which equally absorb the photons, but do not convert them into a useful signal, instead convert them into heat, which is detrimental. This 1 MP sensor has sufficient resolution to resolve enough detail for a very small print, and with today's tech you could probably use it at 204,800 ISO or more with very low noise (and before any of you reply that you can reduce the size of the image and therefore reduce noise and equally obtain the print, try exposing a 36 MP sensor at 204,800 ISO or higher if you can...).



You started to get there with the one photodiode bit...then you lost it. 



pierlux said:


> Again, the same sensor with 20 MP exposed in the same conditions does not collect 50 photons per photosite, but MUCH LESS this time due to massive wiring and lots of wasted space between photosites, so you have a high resolution image, but with a lot of noise.



You are correct, smaller pixels collect less light per photodiode. _IN THE PAST, there WERE losses due to fill factor._ Because wiring and transistors used up some die space, incident light that struck any non-photodiode space would either reflect or convert to heat. _THAT IS NO LONGER THE CASE TODAY!_ Technology has improved considerably, with microlenses, BSI sensors, deep photodiodes, increased charge hole density, and a whole host of other improvements. 



pierlux said:


> Actually, in my example with 1,000,000,000 total photons hitting a 24 x 36 mm sensor I think you'd have only random noise at 20 MP, but it was for the sake of explaining. I'm not talking quantum efficency at all here, it's just the number of photons you can effectively use I'm talking about. Moreover, we don't have a linear relationship between number of photons and noise, so it's not as if you have half of the photons per photosite you double the noise, the situation is worse in the real world.



You are correct about the non-linear relationship that noise has with signal strength. However, you are forgetting about the relationship of smaller pixels to larger pixels, and the impact that *averaging smaller pixels together *has on noise. If you have 10µm pixels, they gather four times as much light as 5µm pixels. Now, let's say out 10µm pixels have a *full well capacity (FWC)* of 100,000 electrons, or 100ke-. The 5µm pixels have a FWC of 25ke-. In terms of photon shot noise, the larger pixels have SQRT(100,000), or ~316e- noise, while the smaller pixels have SQRT(25,000) or ~158e- noise. If we simply ADD the noise of four smaller pixels together, we get 632e-. Oh no, more noise!! 

Your forgetting that noise is not simply added together when normalizing...it is AVERAGED. We do get a total of 632e- noise in a 2x2 matrix of five micron pixels, however if we average those pixels together by downsampling the larger output image from the sensor with smaller pixels to the same dimensions as the output image from the sensor with larger pixels, the noise factor drops by the square root of the difference in in pixel count. Since we can fit FOUR times as many five micron pixels in the same area as ten micron pixels, the 632e- noise drops by a factor of SQRT(4), or 632e-/2, which is? Oh, look at that...316e-!! *Smaller pixels are NOT noisier on a normalized basis.*



pierlux said:


> The Canon 1Dx is 18 MP; in the Nikon D800, being 36 MP, each photosite collects LESS than one half of each of the Canon's photosites, that's why the 1Dx is much better in low light. And the D800 holds because of its superior sensor tech (let's face it, fortunately Canon's system is better as a whole), otherwise they wouldn't have made it 36 MP in the first place.



The 1D X does marginally better in low light. No camera does "much better" in low light, because at high ISO, we are primarily physics bound. But lets use some real numbers here. The 1D X has an FWC of 90367e-, and the D800 has an FWC of 44972e-. Now, that is the full well capacity, the maximum amount of charge each pixel can hold. If we just compute the grant total amount of light both sensors can gather if they were exposed to maximum saturation:


```
1DX: (5205px*3533px)*90367e-/px = 1,661,782,710,255e-
D800: (7424px*4924px)*44972e-/px = 1,643,986,358,272e-
```

The 1D X has slightly more. In terms of percent, if we divide those two numbers, we get:


```
((1,661,782,710,255e-/1,643,986,358,272e-) - 1) * 100= 1.0825%
```

The 1D X has a GRAND TOTAL light gathering capacity lead over the D800 of ONE PERCENT. That's it! One percent. Now, let's look at high ISO. At ISO 12800, the 1D X has a saturation point of 735e-, and the D800 has a saturation point of 507e-. The 1D X's pixels should do much better, right, because they are so much larger? Hmm, not according to the math:


```
1DX: (5205px*3533px)*735e-/px = 13,516,109,775e-
D800: (7424px*4924px)*507e-/px = 18,533,778,432e-
```

The D800 should be suffering because of it's smaller pixels. Each one, after all, is gathering LESS total light at ISO 12800 for any given exposure than the 1D X. However, in terms of absolute amount of light gathered...


```
((18,533,778,432e-/13,516,109,775e-) - 1) * 100 = 37.12%
```

Fundamentally, ignoring any other factors for the moment (I'll get into those shortly here), the D800, despite it's smaller pixels, is actually gathering THIRTY SEVEN PERCENT more light in total! That not only demonstrates the point that smaller pixels don't really have anything to do with light gathering capacity, but it also speaks volumes to the technology in the Exmor sensor. 

Now, these numbers don't jive with tests. Why? Pixel size does not matter when it comes down to how much light a given sensor, regardless of it's pixel size, can gather. If you know anything about equivalence, you know that the primary thing that really matters from the standpoint of noise is total light gathered. This is why larger sensors perform better than smaller sensors, and always will (given they both use the same technology.) 

So, why does the 1D X perform better at high ISO? Canon currently has Correlated Double Sampling (CDS) technology that performs better than Sony or Nikon's, so their dark current is extremely low at high ISO, and because of their use of a bias offset, Canon's read noise (dark current plus downstream RN) is lower in total. The 1D X has 1.6e- RN at ISO 12800, vs. the D800's 3.3e- RN at ISO 12800. That leads to increased dynamic range at high ISO, which gives the 1D X the edge:


```
1DX: 20*log(735/1.6) = 53.24dB
D800: 20*log(507/3.3) = 43.72dB
```

The 1D X has ~8.8 stops of dynamic range at ISO 12800, while the D800 has ~7.3 stops. Ironically, the technology that flattened the read noise floor for Exmor, and gave it a significant lead at low ISO, actually seems to hurt it a bit at high ISO (at least, in the D800).

Why does the D800 suffer here? When it comes to dynamic range at high ISO, pixel size does matter, because it affects the maximum amount of charge that can be held in each pixel. Since dynamic range is the ratio between saturation point and read noise, _the *higher read noise* of the D800 at high ISO costs it the lead it had at low ISO._ If the D800 used a bias offset the same way Canon does, the offset could then be used to minimize read noise at high ISO. The D800 with 0.5e- read noise at ISO 12800 would have a dynamic range of 60dB. The D810 now actually uses a bias offset, and it's read noise drops to a very low 1.3e- at ISO 51200.



pierlux said:


> In the pizza analogy, the more you cut the pizza, the more breadcrumbs, morsels, atomies you produce, leaving the eaters with less and less pizza to eat to the point that, putting together all the slim slices of pizza eaten by all, they add up to not even a quarter of the original one. And, actually, a pie should be a better fitting analogy.



Sure, there are crumbs and other small losses. However, those losses are small. Not just small, minuscule. They are, for all intents and purposes, meaningless. You could even shave off a little bit off the sides of each pizza slice (which often happens when using a classic pizza cutting wheel), and it would still largely be meaningless in terms of the grand total area of pizza that is still eaten. 

Plus, the pizza crumb analogy ignores technological improvements in sensor design. Modern sensors are NOT just an open matrix of photodiodes and exposed wiring and transistors. Moderns sensors use one of two designs: *Front Side Illuminated (FSI)* and *Back Side Illuminated (BSI)*. An FSI design does have wiring and transitors on the face of the sensor, however they no longer receive incident light in a modern sensor design. Canon started using microlenses a few generations ago, and all their current sensors use gapless microlenses. Microlenses direct incident light through the CFA and onto the photodiode. Sony sensors now actually use a double layer of microlenses...an upper layer that directs incident light into the CFA, and a lower layer that directs any dispersed light that actually makes it through the CFA into the photodiode. (Part of the reason why Sony sensors have better Q.E.) That cuts the losses due to fill factor to nearly nothing. There are still losses, but they are a tiny fraction of what they used to be. Fill factor is now no longer the concern it used to be. 



pierlux said:


> It's like having a 100 x 100 ft room all for yourself, 10,000 square feet is plenty of space. But if you want to accomodate 100 people inside it and offer them a bit of privacy, you have to build walls which eat space, not to mention furniture, so you end up with much less than 100 sq. ft for each dweller.



The primary concern with fill factor now is grand total photodiode area. Smaller pixels have smaller total photodiode area, and since historically the only thing that mattered from a total charge capacity standpoint was the area of the photodiode, smaller photodiodes hold less charge than larger photodiodes. The greater losses in sensor die area that can be dedicated to photodides when using smaller pixels can affect the grand total amount of light that a sensor with smaller pixels gather. A 10µm pixel fabricated with a 500nm process will have 9µm square photodiodes, where as a 5µm pixel will have 4µm square photodiodes. Instead of a 4x difference in area, that's a 5x difference.

A BSI sensor does not have these problems. With a BSI design, all of the wiring and transistors are relegated to the "front side", and the photodiodes, CFA, and microlenses are placed on the "back side" of the sensor substrate. This effectively gets you a 100% fill factor. Generally speaking, any sensor technology that can be used for smaller sensors can be used for larger sensors. Technically speaking, BSI COULD be used for large full frame sensors, however because of the fact that both sides of the silicon substrate are etched, the increase in fragility results in a yield that is well below acceptable for larger sensors (at the moment this includes APS-C sensors, however there are some patents out there that cover means if strengthening the wafer to allow larger sensors than 1/2" to be fabricated with a BSI design.) 

A small BSI sensor will have a nearly 100% fill factor as far as the back side goes. Therefor, there are no losses in die space, and since BSI is a benefit that only smaller sensors can use currently, it normalizes the playing field. The differences in photodiode capacity even for FSI are largely moot these days, with new techniques allowing "deep photodiodes", where the fundamental silicon doping and structure of the photodiodes themselves can be tweaked to increase charge capacity with depth as well as area. There are even patents that describe means of increasing_ "electron hole density"_ in a photodiode, allowing greater charge to be stored in a smaller photodiode area. The more sensor technology marches on, the less _fill factor_ will play a role in grand total light gathering capacity. 

If we ignore _furniture and other accomodations_, which really have absolutely ZERO relevance to a sensor analogy...then your walls don't really reduce the capacity. We could still fit 100 people in a 10,000 square foot room if we added walls. The people would just be more densely packed. We would need to pack in a lot more than 100 people into 10k square feet before the addition of walls started to matter. The walls eventually would matter, once you start packing in more people into smaller and smaller rooms...however that's where BSI sensor designs come into play. You then build another floor on top of the walled rooms, and move everyone upstairs. Suddenly, you have plenty of room again.



pierlux said:


> Still not convinced? OK, you may say "who are you to stand up and make such claims against my maths?", so let's look at what Canon's engineers have done, I bet they know more than me or anyone else on CR about silicon performance and noise. This is what I wrote in a previous post:
> 
> "There's a reason the 1Dx has the best (to my eye) IQ of all the DSLRs available to date (yes, better than any Nikon I think): its 18 MP FF sensor. And there's a reason why Canon developed a prototype sensor with photosites 7.5 times larger than the 1Dx: to capture quality video in candlelight (candledrkness sounds better, though). Don't know if you remember, but check these:
> 
> ...



Yup, still not convinced.  

The 1D X's high ISO performance, as I *ACTUALLY *demonstrated with *REAL *math, is not primarily due to it's pixel area. In terms of pixel size, total sensor area, and sensor efficiency (Q.E.), the D800 is actually 37% more efficient than the 1D X at ISO 12800. The difference between the 1D X and the D800 at high ISO is actually the amount of read noise...the 1D X's lower read noise gives it more dynamic range, and THAT is what makes it better. Read noise has more to do with sensor technology and complimentary electronics (i.e. ADC unit) than it does with pixel size...so again, sorry...but your still wrong.


----------



## Vgramatikov (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*

Hello again.
www.500px.com/Vgramatikov
I`m wildlife photographer.

If i have to use not to many words i would say:

In practice lower count megapixels is better than higher count simply because of the workflow.
I speak like wildlife photographer. Shooting sports, fast moving subjects and so on is better with lower mp.
Higher mp is always better and effective if the sensors in same production design and innovation BUT.
When we use fast cameras like 7d/ii we use them mainly for fast moving subjects in natural light.
Bigger count is better but bigger count means lot more post to get good image. That why d4 and 1dx are lower count mp cameras. Because for sport and wildlife higher count means usually slower frame rate, short buffer, lot more work in post.
I prefer 16mp on crop camera than 20+....i loose all that extra resolution due to lower shutter counts, not perfect optical design of the lens, motion blur and so on.

If you just check how 300 2.8 mk2 IS perform on 1ds iii in DXO showing 21mp of 21mp resolving power.
Witch means almost perfect lens for this size/mp sensor.
Same lens on Canon 70d produce 17mp from 20mp. This means 3mp is throw away due to smaller sensor. And this is in perfect test conditions. On the field you will throw out even more 10mp for sure.
That why d4 and 1dx are lower count mp. Cause it is no sense to use higher count mp camera for sports and wildlife.

I prefer better work flow, bigger buffer, cleaner images, more DR and less mp.

But for aps-c sensors is already impossible someone to announce 16mp sensor.
If i can make i wish. I want 7d ii with some kind of Fuji interpretation of Sony 16mp sensor and 40-50 RAW buffer.

Just check the Nikon d7100....good camera, good sensor and only 6fps and very very slim buffer....this is a one big joke in practice. 7d have 24 raw buffer with 8fps and 18mp sensor way way better if i`m not wrong for the details.

Sorry for bad english again!!!
Good luck and don`t worry 7d ii will be perfect as any canon body. But it will be crop sensor camera. Do not expect 6d low iso performing. Just may be little better than my 70d. But like instrument will be lot better.

I don`t care about +2 stops of DR for Sony sensors in the range 100-800 iso because i do not use very much iso 100-400 when i m on the field. When i take landscapes canon is just fine. None of my images will become better with 2 stops more DR at iso 100 

If i was a landscape or portrait photographer i will go for Canon 6d or Nikon d610. Not hard choice.
But for wildlife. The best balance between cheaper and better is for sure 7d,70d available cameras and future 7d ii. Canon was the greatest long telephoto lenses starting from 400/5.6L.

None of the companies have lens like this. I have my own 300 2.8 IS mk1 and 600/4 for the past. 
Canon 400 5.6L is sharper than 600f/4 IS mk1 and as sharp or better than 300 2.8 IS mk1 + 1.4
Sold 300 2.8 and buy 200 2.8L for low light 500 euro and 400 5.6L for main telephoto lens for 700 euro.

Who cares about the sensors if they are just fine ! Not greater ?!


----------



## Lee Jay (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Vgramatikov said:


> If you just check how 300 2.8 mk2 IS perform on 1ds iii in DXO showing 21mp of 21mp resolving power.
> Witch means almost perfect lens for this size/mp sensor.
> Same lens on Canon 70d produce 17mp from 20mp. This means 3mp is throw away due to smaller sensor. And this is in perfect test conditions. On the field you will throw out even more 10mp for sure.



And, at the same range, the 21MP will be reduced by a factor of 1.6^2 (2.56), leaving 8.2MP.

In other words, the larger sensor only has an advantage if you can use a larger lens or wait until the subject is closer. At the same range, it has a disadvantage because of its large pixels.


----------



## RodS57 (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Mt Spokane Photography said:


> cnardo said:
> 
> 
> > But if Canon said: "Canon today announces DETAILS of it presence at Photokina 2014..." where are they ??????
> ...



That's it! That explains everything. Every time a Canon employee leaks something the release date for the new 7D is pushed out by 2 months. That is why it has taken so long and why it is so hard to find information.


----------



## Famateur (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*

@Lee Jay: Thanks for the detailed replies. Reducing noise at the expense of resolution -- that sums it up well, I think.

In the past (and this is often how it's presented by "experts"), I've thought that, given identical sensor technology, going from 20.2MP to 24MP would just translate into more noise, and I guess it does, but if I scale it back down to 20.2MP, I haven't lost anything -- or maybe even slightly gained. Then in optimal conditions, I have more resolution, and in noise-producing conditions, I can scale the image down and be no worse off than the 20.2MP version of the same sensor tech.

Does that sound right? If so, then bring on the pixels! I wouldn't mind the flexibility to compress for noisy images and have extra resolution for low-noise images.

---

Interesting stuff. I'm open to explanations if anyone else wants to add, but this seems to make sense...


----------



## jrista (Aug 29, 2014)

*Re: EOS 7D Mark II & Photokina*



Famateur said:


> @Lee Jay: Thanks for the detailed replies. Reducing noise at the expense of resolution -- that sums it up well, I think.
> 
> In the past (and this is often how it's presented by "experts"), I've thought that, given identical sensor technology, going from 20.2MP to 24MP would just translate into more noise, and I guess it does, but if I scale it back down to 20.2MP, I haven't lost anything -- or maybe even slightly gained. Then in optimal conditions, I have more resolution, and in noise-producing conditions, I can scale the image down and be no worse off than the 20.2MP version of the same sensor tech.
> 
> ...



Yup. You pretty much have it. Assuming equivalent or better sensor technology, more pixels is never bad. It may not necessarily be better, beyond the core theory a lot of factors play a role...but more pixels can pretty much never be bad, certainly not worse.

The reason that full frame sensors usually perform better than APS-C sensors is the greater total area. If you frame identically with both cameras, then the larger the sensor, the more total light your gathering. That means less noise (on a normalized basis), and usually, even though the pixels tend to be bigger, more detail (since your getting more pixels onto the subject than you can with a smaller sensor.) 

The only real caveat to the above is reach-limited situations. In those cases, smaller pixels will always resolve more detail than larger pixels. Doesn't necessarily matter if they are in a smaller sensor (although they usually are)...all that matters is that when you are at a fixed distance from your subject with a specific lens, your subject is going to fill the same absolute sensor area regardless of how big the sensor is. Then, smaller pixels mean more detail.


----------



## pierlux (Aug 30, 2014)

*Re: EOS 7D Mark II & Photokina*

Lee Jay, jrista, and also sarangiman , sorry for the delay, but my ex-wife lives 40 km away from me so it took me a while. Plus, I'm very slow in writing.

Thank you guys for the effort spent in replying, you almost convinced me. I think I have to re-read your replies another couple of times to fully understand all, but I'm nearly convinced. I have a couple of questions. I still don't get what


Lee Jay said:


> ...the 2.04 micron pixels of the S3IS provide better IQ behind the same lens as the 8.2 micron pixels of the 5D.


actually means. Problem is, comparing sensors having different resolution, we are far from "all the other conditions being equal" here. Are you sure those images are ISO 800? My old 6 MP 300D at 800 ISO is noisy as hell, and it's APS-C. The fact is that I still have problems in regarding normalization as a fair mean of comparison.

Moreover, I still think the following logic is flawed. jrista, you say 


jrista said:


> Your only thinking about the individual pizza slices here. Your missing the bigger picture: The eater who eats 1/6th of a pizza eats 1/6th of a pizza SIX TIMES!! Therefor, the eater is not eating one pizza slice...*the eater is eating A WHOLE PIZZA!* ;D _This is the critical point that everyone seems to miss._ If an eater eats two 15" pizzas, one cut into 6ths and one cut into 8ths...has the eater eaten less total pizza when eating the one cut into 8ths? NOPE!! He's still eaten a whole 15" pizza, same as he did when he ate the one cut into 6ths.


but I still think the eater here is not the whole sensor, it's each individual photosite. If the eater was the whole sensor, you'd obtain zero resolution, no detail. But you need detail to produce a meaningful image, so you must compare the eater to the single photosite. So the more the eaters (the higher the resolution), the less amount of pizza each eater eats.

I know BSI sensors have the wiring on the opposite side, and that large sensor only marginally benefit from this configuration, that's why this more expensive and lower yield technology is not used in larger sensors, but this is true for (relatively) low density photosites per area unit. The higher the density, thus the smaller the photosites, the greater the benefit. I don't know the numbers, but are you sure the wiring of conventional sensors matter so little in the light blocking effect on the photosites? Does a 24 MP APS-C sensor, even at 180 nm, still marginally suffers from the interposed wiring? jrista, it seems you know where to find such information, I'd like to deepen my knowledge, why don't you post the most interesting links you find, every now and then, on CR? I mean not now, don't get me wrong, but you're one of the most active posters here, I'm sure at least some CR members would appreciate some technical reading sometimes, I for sure.

Thank you all guys, it's very late here, good night!

Ah, my son and I had pizza for dinner, irony!


----------



## dgatwood (Aug 30, 2014)

*Re: EOS 7D Mark II & Photokina*



pierlux said:


> but I still think the eater here is not the whole sensor, it's each individual photosite. If the eater was the whole sensor, you'd obtain zero resolution, no detail. But you need detail to produce a meaningful image, so you must compare the eater to the single photosite. So the more the eaters (the higher the resolution), the less amount of pizza each eater eats.



The eater ate the slices at different times. The total number of pepperoni slices consumed are still the same whether the person counted them on the entire pizza all at once or on each piece of pizza individually. By counting them a slice at a time, you get more detail about their distribution, but they still contribute the same amount to your total fullness either way.


----------



## jrista (Aug 30, 2014)

*Re: EOS 7D Mark II & Photokina*



pierlux said:


> Lee Jay, jrista, and also sarangiman , sorry for the delay, but my ex-wife lives 40 km away from me so it took me a while. Plus, I'm very slow in writing.
> 
> 
> 
> ...



Your still thinking about it wrong. The eater is not the sensor, nor the photosite. The eater is light. The pizza is the sensor. The slices are the pixels. When you create an exposure, light illuminates the ENTIRE sensor...not only one or two or ten thousand pixels...but the whole thing. 

Hence the analogy. The eater is light. The eater is always eating a WHOLE PIZZA. It doesn't matter if that pizza is sliced into 6ths, 8ths, 12ths, or 40 millionths. The eater is STILL going to eat the whole darn thing....every single time (i.e. every single exposure). 

Make sense now?




pierlux said:


> I know BSI sensors have the wiring on the opposite side, and that large sensor only marginally benefit from this configuration, that's why this more expensive and lower yield technology is not used in larger sensors, but this is true for (relatively) low density photosites per area unit. The higher the density, thus the smaller the photosites, the greater the benefit. I don't know the numbers, but are you sure the wiring of conventional sensors matter so little in the light blocking effect on the photosites?



Yes, I am sure. It used to matter, but that was near a decade ago now. Canon was using microlenses almost that long ago, and that alone changed the game considerably. Pretty much everyone is using gapless microlenses, and some are using two layers of microlenses. The non-sensitive die area is no longer blocking, reflecting, or absorbing much light. It's a percent or two, which has a small impact on overall Q.E., but it isn't significant enough to worry about.

A vastly more impactful issue is the use of a CFA itself. The color filter over each pixel is reflecting anywhere from 60% to over 70% of the incident light!!! The CFA is the real killer of sensitivity, by a very, very LONG shot. The small differences in photodiode area are pretty minor these days when talking about pixel sizes 4µm and larger. Canon is actually suffering a lot more because of that than their competitors...their process is 500nm. I have long suspected that Canon has not made a 24mp APS-C sensor yet because that would put them into a pixel pitch range where the 500nm wiring and transistor size WOULD hurt the performance of smaller pixels (i.e. fill factor, DESPITE the use of microlenses, becomes an issue again, simply because the ratio of photodiode area to total die area is too small). 

Most other manufacturers are making sensors with 180nm or smaller processes. At 180nm, the difference between a 4µm pixel and a 6µm or 10µm pixel are pretty moot. There is a small percentage difference, but it doesn't generally amount to significant enough differences in total light gathering capacity that it matters in the grand scheme of things. I mean, look at the D800 vs. 1D X. The former has only a 1% loss vs. the latter at low ISO, and a massive 37% LEAD over the latter at high ISO. Granted, the D800 has better technology...it's got a Q.E. of 56%, the sensor does use a 180nm fabrication process, it's got better microlensing, etc. The 1D X only managed to scrape back the lead because Canon's analog CDS is (currently) superior at higher ISO. 


Anyway...the use of microlenses, light pipes, BSI designs, etc. pretty much negates the fill factor issue. The remainder of the issue is being resolved with tall photodiodes, materials science that allows more electrons of charge to be held in a smaller photodiode area, etc. At some point, I figure all sensors will be BSI with some kind of reinforcement technology to keep the sensor substrate rigid, minimizing yield losses. When every sensor is BSI, the whole fill factor issue will be gone for good. 



pierlux said:


> Does a 24 MP APS-C sensor, even at 180 nm, still marginally suffers from the interposed wiring? jrista, it seems you know where to find such information, I'd like to deepen my knowledge, why don't you post the most interesting links you find, every now and then, on CR? I mean not now, don't get me wrong, but you're one of the most active posters here, I'm sure at least some CR members would appreciate some technical reading sometimes, I for sure.



I periodically have these sensor patent and technology binges.  I dig around looking for the latest and greatest news on what the image sensor world is doing, find and read patents (if I can, that's often a MAJOR PITA, as a lot of patents are only written in Japanese, and translating them can be a confusing endeavor.) I regularly read http://image-sensors-world.blogspot.com/ and browse through http://www.chipworks.com/ for the latest teardowns. Those two places are usually where I learn about new technology, and from there, I'll go digging for more information. 

One thing to note...the VAST majority of the high end sensor technology I talk about is actually only really used in tiny sensors. Stuff 1/2" size of smaller, the kind of sensors used in hand held devices, cars, specialized video cameras, etc. Even though Sony's FF and APS-C sensors are currently the creme of the crop, and Canon's are up to a couple generations behind just about everyone at this point...in the grand scheme of things, FF and APS-C sensor technology across the board is quite primitive. There are some AMAZING things being done at the ultra tiny end of the scale. Were talking about pixel sizes of 1.4µm, 1.2µm, and 1.1µm are the current smallest generation. Most new small form factor sensors are 1.2 and 1.1 microns in size, however soon they will be reaching the theoretical limit for visible light image sensors, 0.9µm or 900nm. At 900nm, were starting to close in on the bandwidth of visible light, which ranges from around 750-800nm down to 320-380nm. (To my knowledge, light cannot pass an aperture smaller than it's wavelength. At some point, someone may figure out a way to get around that hurdle, but so far, I think that the 900nm pixel pitch is considered the minimum size for a pixel such that the luminous flux of an incoming wavefront can actually pass through the pixel aperture, or be refracted by a microlens, and still reach the photodiode.)

It took a lot of innovations just to make 1.4 micron pixels possible, and the current cutting edge 1.1 micron pixels required even more not just to be possible, but to still have enough sensitivity to be useful. Keep in mind, many of these sensors are only 1/8th of an inch in size at their largest, so the total light gathering capacity is minuscule. The proliferation of video into everything, including phones and tablets, now the booming market for car rear view video, etc. has demanded a level of high speed sensitivity that still cameras never dreamed of. That's where we got innovations like black silicon (similar to Canon's SWC lens nanocoating), which significantly increases the absorption rate of incident photons, multibucket pixels for high dynamic range, color splitting filters as an alternative to color filter arrays that don't waste any light, and a whole host of other improvements that radically improve the overall quantum efficiency of devices in very low light at high frame rates. Other innovations have succeeded in reducing dark current to practically meaningless levels (current generation FF and APS-C DSLR sensors have massive amounts of dark current...at their operating temperatures, probably as much as many electrons per second of exposure, so CDS and bias offsetting or black point clipping was essential to minimize dark current signal and reduce thermal noise)...dark current levels in modern cutting edge sensors is as little as a small fraction of an electron per second (in other words, it takes many seconds for even one electron to be freed in a pixel due to dark current). 

I have an ultra high sensitivity 74% Q.E. Aptina sensor in my guide and planetary camera that I use for astrophotography. It has dark current of about 0.005e-/px/s. Sony's new ExView II CCD sensors (used in thermally regulated CCDs for astrophotography), which have 77% Q.E., have dark current of 0.003e-/px/s or less! Both of these sensors come in 1/2" and 1/3" varieties...so they are pretty small, half the size or less of an APS-C.

At some point, I figure the technology from the cutting edge, and ultra small, will eventually work it's way up to the larger form factors. However, on the SENSOR innovation front...the only things Canon has shown in the last couple of years are DPAF and a couple multi-layered sensor patents. Canon is an innovative company, however it seems most of their innovation is focused in areas other than image sensor development. In the same time frame, Aptina, Sony, Omnivision, Toshiba, and a number of other major players in the sensor market have filed as many as dozens of patents for sensor technology...each. If and when these cutting edge 1.1 micron sensor technology innovations find their way into FF and APS-C sensors...I don't suspect it will be Canon who does it first.


----------



## LetTheRightLensIn (Aug 30, 2014)

*Re: EOS 7D Mark II & Photokina*



serendipidy said:


> The problem with the basic laws of physics is that our understanding of them has always been incomplete. They still are.



yeah, but you have to admit that collecting more photons than are hitting a scene seems to be a problem of a different level....


----------



## LetTheRightLensIn (Aug 30, 2014)

*Re: EOS 7D Mark II & Photokina*



Lee Jay said:


> Famateur said:
> 
> 
> > Dare I wade into the pizza war?
> ...



although most DSLR sensors still waste some space that could be used for the well size etc., I believe
some P&S sensors I believe get around this by going to backside and so on though so the tech is already there to get around it pretty much, it is more expensive, especially on FF sensor size though so they haven't yet bothered with it since the cost is not yet worth it for the tiny gains at this point (if FF went to super high MP then BSI and so on would help enough for some to maybe want to pay the extra)

at ultra high MP counts compared to really low MP counts using current FF DSLR methods the ultra high MP might start showing reduced performance, but for the type of tech currently used, I don't think the MP counts of the highest DSLRs are high enough yet for it to really noticeable matter (and they do have options for when it would start to matter a bit (and evne with SOny RS100, very high density and BSI helps but it's really not anything all that radical at all of a difference)


----------



## x-vision (Aug 30, 2014)

*Re: EOS 7D Mark II & Photokina*



jrista said:


> Assuming equivalent or better sensor technology, more pixels is never bad.



You mean assuming _better_ technology only. 
For equivalent technology, this works only up to a point - at least for front-illuminated sensors.

In a front-illuminated sensor, the photodiode of a pixel is located at the bottom of a well, basically (see the left diagram): 







The well is formed by the layers of metal wiring above the photodiode. 

As pixels shrink, this well becomes narrower and narrower. 
At some point, the well becomes so narrow that the micro-lenses on top can no longer focus the light on the photodiode.
This leads to light losses - and the resulting image quality degradation.

Thus, to further shrink the pixels, you need to switch to a finer CMOS process (or maybe BSI).

The likely reason that the 5DIII has 'only' 22mp is not because Canon no longer believes in megapixels (they do).
Rather, Canon appears to have hit the shrinking limit of their 500nm CMOS process, on which the 5DIII sensor is made.

The 70D is likely made on a finer CMOS process (180nm?), though, as I can't imagine that they've
been able to stretch their 500nm process to make the 20mp/dual-pixel sensor of the 70D. 

So, smaller pixels are indeed generally better.
It's not a free ride, though; there limits as to how much you can shrink with a given technology.
Beyond that, you need to change your technology - or image quality degrades with smaller pixels.


----------



## jrista (Aug 30, 2014)

*Re: EOS 7D Mark II & Photokina*



x-vision said:


> jrista said:
> 
> 
> > Assuming equivalent or better sensor technology, more pixels is never bad.
> ...



I know exactly what a sensor pixel looks like.  I also know that manufacturers have been using a double layer of microlenses to solve the problem with the FSI design you showed. They have been for years. I know some BSI designs even use double microlens layers. Further, I know Canon has a small form factor sensor design that uses a double layer of microlenses AND a lightpipe in an FSI design to minimize the problem even further. I'll raise your crude diagram with an actual cross section electron micrograph of Canon's 180nm Lightpipe sensor with Cu-interlinks (note, this is a rather old image, from about two years ago...Canon moves slowly, but I'd certainly hope they have sensors using BSI for pixels this small now...also note, given this is a 180nm process, the pixels pictured here are really quite small, I'd say less than 2 microns, so don't take this as an example of FF or APS-C fill factor):






As I said. Technology has been marching on. The simplistic grid of photodiodes and bare wiring/transistors is a thing of the past. Even gapless microlenses are a thing of the past. For really small pixels, BSI is ubiquitous these days, and we know Canon has some patents for BSI technology as well...so even the double-microlens layer/lightpipe design from the image above is a thing of the past.


I do agree that Canon is probably at the limits of the 500nm process, at least on a competitive front. They already make pixels much smaller than the 5D III's in their APS-C sensors, so they aren't at the limit of the process for their FF parts. They are obviously at the limits of their ability to remain competitive at 500nm for those larger sensors, though.


----------



## x-vision (Aug 30, 2014)

*Re: EOS 7D Mark II & Photokina*



jrista said:


> As I said. Technology has been marching on.



Right. 

But even with light-guides (to guide the light onto the photodiode), there are still limits as to much you can shrink pixels.
These are physical entities and you cannot shrink them indefinitely with a given technology. 
The light guide cannot have a diameter zero, which is obvious even from the picture you posted - if your keep shrinking the pixels. 

You make it sound as if smaller pixels are always better - and that's not unconditionally true. 
That's the only point that I'm making. 

There's a physical limit that cannot be crossed. 
That's why manufacturers are using finer and finer CMOS processes (Panasonic is down to 65nm now).
And also looking for alternative solutions - like BSI, Sony's stacked technology, etc..

So, smaller pixels are generally better - but only when newer, more advanced technologies are used. 

There's also the issue of the full-well capacity of a photodiode.
Smaller full-well capacity automatically lowers SNR. You should know that.

So, it's a balancing act, really, for pixel engineers.
A blanket statement like 'smaller pixels are always better' is just that - a blanket statement.
Some necessary small print needs to be added to discussion 8).


----------



## jrista (Aug 30, 2014)

*Re: EOS 7D Mark II & Photokina*



x-vision said:


> jrista said:
> 
> 
> > As I said. Technology has been marching on.
> ...



Sure, there is no question there are limits to how small you can shrink pixels with an FSI design. I already mentioned that ALL small form factor sensors that use 1.2µm pixels and smaller use BSI designs now. 

But we are primarily talking about larger sensors. In larger sensors, we don't have the kinds of problems with maintaining incident light ratio on the photodiodes. We don't even need lightpipes...a single layer microlens works sufficiently to control over 90% of the light. A second layer would again focus any dispersal from the color filter back into the "well", again minimizing any remainder losses. 

There is also a limit to how far use of finer processes will improve things for larger sensors. For smaller sensors they are essential, even with BSI, as your packing so much into increasingly small spaces. I mean, when the 0.9µm generation hits, the pixels will be smaller than the majority of the infrared bandwidth! But, large sensors still have huge pixels. It will be many generations before we drop below 3 micron pixels, assuming we ever do. It's a lot harder to make large optics perform well outside of the central FoV, and I think lens design will ultimately become the bottleneck for keeping the megapixel race alive with larger sensors. 

Assuming we do reach 3 micron pixels at some point, on either a 180nm or 90nm process...that would be a 96 MEGAPIXEL sensor in full frame, and a 37 megapixel sensor in APS-C. That's WAY up there. The highest resolution sensors will probably sit around 4.5µm to 3.7µm pixel sizes for a while still, a couple DSLR generations, which puts us out another eight years approximately? 

Assuming everything is manufactured on a 180nm or smaller process soon, I don't think that fill factor will be the primary or even a significant issue for APS-C and FF sensors for so long that it simply doesn't matter. In that light, I still assert that you can always do more with smaller pixels. As far as I am concerned, BRING ON THE 96mp MEGAPIXEL MONSTROSITIES!! MUHAHAHA!!


----------



## x-vision (Aug 30, 2014)

*Re: EOS 7D Mark II & Photokina*



jrista said:


> Sure, there is no question there are limits to how small you can shrink pixels with an FSI design.



Yup. That's the clarification that I was after .



> As far as I am concerned, BRING ON THE 96mp MEGAPIXEL MONSTROSITIES!! MUHAHAHA!!



LOL! 

You are laughing but I bet that they are going to do it in 10 (?) years.


----------



## jrista (Aug 30, 2014)

*Re: EOS 7D Mark II & Photokina*



x-vision said:


> jrista said:
> 
> 
> > Sure, there is no question there are limits to how small you can shrink pixels with an FSI design.
> ...



Oh, I'm laughing because I KNOW they are going to do it. Some people laugh at the megapixel race, but me, I'm all for it. I want as much resolution and dynamic range as I can get my hands on, particularly for landscapes.


----------



## crashpc (Aug 30, 2014)

*Re: EOS 7D Mark II & Photokina*

If one can see moire in the image, there is not enaugh resolution on sensor, and we are not lens limited yet. Waiting fo 64Mpx APS-C cam. muhahaha...


----------



## jrista (Aug 30, 2014)

*Re: EOS 7D Mark II & Photokina*



crashpc said:


> If one can see moire in the image, there is not enaugh resolution on sensor, and we are not lens limited yet. Waiting fo 64Mpx APS-C cam. muhahaha...



Actually, if one can see moire in the image, they have an improperly designed AA filter.  We don't NEED to significantly oversample the lens to avoid moire. We've been avoiding moire for over a decade...the problem today is that manufacturers are removing the AA filters while we are still often UNDERsampling the lens. Moire shouldn't be a problem...the fact that it is, is because photographers and manufacturers are artificially making it a problem by systematically weakening and entirely removing AA filters from cameras that were doing just fine with them before.


----------



## Famateur (Aug 30, 2014)

*Re: EOS 7D Mark II & Photokina*

Jon, Lee, thanks for all the info. It's been enlightening.

Cheers!


----------



## crashpc (Aug 30, 2014)

*Re: EOS 7D Mark II & Photokina*



jrista said:


> crashpc said:
> 
> 
> > If one can see moire in the image, there is not enaugh resolution on sensor, and we are not lens limited yet. Waiting fo 64Mpx APS-C cam. muhahaha...
> ...



We have different angle of view on that. I tried to point to a fact that if you see moire, the lens certainly resolves more than sensor itself. That way If we want to up the resolution, increasing sensor resolution still IS the way, as the lens can do that. Of course with some losses, but that´t the deal. Still worth it. If you don´t see moire in the image taken with AAless sensor where it should be, then you´re using your lens resolution potential at its full capabilities, and that´s where we (at least me) we want to go one day. One day nobody will need to be bothered with sensor resolution. It will be absolute compared to lenses we put in front of it, only what will matter will be DR, efficiency, noise supression and stuff. This megapixel fight will move to different aspect.


----------



## jrista (Aug 30, 2014)

*Re: EOS 7D Mark II & Photokina*



crashpc said:


> jrista said:
> 
> 
> > crashpc said:
> ...



In that respect, I agree. We DO eventually want to get sensor resolution to the point that it oversamples, eliminating the NEED for AA filters. Were a pretty long way off from that day, though. If lenses like the Otus are any indication, we can push 400lp/mm from an ultra high quality lens at wide apertures. That means we would need pixels around 1.25µm in size to simply MATCH that resolution, let alone oversample it. The theoretical limit on useful minimum pixel size is 0.9µm (900nm, well into the wavelengths of near-IR light!) A full-frame sensor at point nine microns would be a GIGAPIXEL sensor. Assuming were at least at 16-bit ADC by the time such a sensor arrives, we would need in-camera data throughput of over 2.3GB/s just to process one frame per second, and data throughput of approximately 13GB/s to process six frames per second. 

That kind of technology is beyond extreme. Relatively few things process data at such incredible speeds...high end, high power GPUs are one of the few that come to mind, along with the level three and lower data caches on a CPU. Those devices require considerable amounts of power to operate. 

So, yes, the notion of a sensor that outresolves every lens you can put in front of it is the ideal...it's a very lofty one. I think we may see sensors that outresolve lenses that peak in resolution somewhere between f/4 and f/2.8 at some point, as many current lenses already achieve their optimal near-diffraction-limited resolution somewhere around f/4. Were still talking about sensors with hundreds of megapixels, though, and the data throughput requirements are still rather insane by todays standards. 

That's nothing to say of the hardware requirements for the PC's that would be used to process such images, or all the pixel-peepers who would look at their images and freak out because of how "soft" they look (when, ironically, that's the entire point...to OVERsample. )


----------



## crashpc (Aug 30, 2014)

*Re: EOS 7D Mark II & Photokina*

Yes, I´m pretty aware of that it is not easy to make this work all on the fly today. Also very low sample of users put really extremely good primes on their cams, so as a manufacturer I´d say screw these few. No need to outresolve every lens on this planet. Just average prime as standard 50mm primes and 70-200 glass. This wouldn´t need so much mega or giga pixels. I guess we talk about 64 to 128Mpx for APS-C. Also you´re right about the processing power. That is why and when PC can step in. If you do less processing to the file in your cam, you will manage that data flow with great in-camera buffer (when shooting higher FPS). All this hard work for pixel peepers as I am, can be done in PC lately, where those power hugry graphic cards can take care of highly paralleled computing tasks needed to process your photos. Does it take 150-300Watts of power when it works? Who cares... And if one needs mobility and speed, the in-camera processor will be powerfull enaugh to compress your results to normal (16-32Mpx) image sizes. It´s doable in pretty near feature with slight modesty about ones expectations of speed or handling. It won´t work "just like that" with current tech, but it will work and we can sorry first few shortcomings. Especially Sony is good in throwing new buggy things on the wall and see what sticks


----------



## sanj (Aug 30, 2014)

*Re: EOS 7D Mark II & Photokina*



Canon1 said:


> sanj said:
> 
> 
> > "whatever"! Really? Some facts thrown your way and you disregard it….
> ...



Whokay!


----------



## vlim (Sep 2, 2014)

*Re: EOS 7D Mark II & Photokina*

3 days left and still no news about the real specs of the 7dII and the coming lenses


----------



## Don Haines (Sep 2, 2014)

*Re: EOS 7D Mark II & Photokina*



jrista said:


> A full-frame sensor at point nine microns would be a GIGAPIXEL sensor. Assuming were at least at 16-bit ADC by the time such a sensor arrives, we would need in-camera data throughput of over 2.3GB/s just to process one frame per second, and data throughput of approximately 13GB/s to process six frames per second.
> 
> That kind of technology is beyond extreme. Relatively few things process data at such incredible speeds...high end, high power GPUs are one of the few that come to mind, along with the level three and lower data caches on a CPU. Those devices require considerable amounts of power to operate.


I'm smiling right now because I am waiting for a test to finish.....
I have a 60Ghz spectrum analyzer in front of me that takes 64 bit readings.... 480GB/s... but no way is it portable or affordable


----------



## jrista (Sep 2, 2014)

*Re: EOS 7D Mark II & Photokina*



Don Haines said:


> jrista said:
> 
> 
> > A full-frame sensor at point nine microns would be a GIGAPIXEL sensor. Assuming were at least at 16-bit ADC by the time such a sensor arrives, we would need in-camera data throughput of over 2.3GB/s just to process one frame per second, and data throughput of approximately 13GB/s to process six frames per second.
> ...



Like I said...relatively FEW things process data at such high speeds. CPUs and GPUs were only a couple examples, there are a few other things that can process immense amounts of data per second...but...not many. And, as you stated, your spectrum analyzer is not portable.


----------



## Lee Jay (Sep 2, 2014)

*Re: EOS 7D Mark II & Photokina*



jrista said:


> Don Haines said:
> 
> 
> > jrista said:
> ...



RED has designed an ASIC (like DIGIC for Canon) that processes almost 2 gigapixels per second, including wavelet compression of the raw data.


----------



## sarangiman (Sep 3, 2014)

*Re: EOS 7D Mark II & Photokina*



jrista said:


> I want as much resolution and dynamic range as I can get my hands on, particularly for landscapes.



And yet you shoot Canon... ???

Just FYI - initial data suggest the dynamic range of the Nikon D810 at ISO 64 approaches that of the medium format Sony sensor inside the Pentax 645z (amongst others) at ISO 100.


----------



## jrista (Sep 3, 2014)

*Re: EOS 7D Mark II & Photokina*



 sarangiman said:


> jrista said:
> 
> 
> > I want as much resolution and dynamic range as I can get my hands on, particularly for landscapes.
> ...



Are there any reasons why you wouldn't buy Nikon? Aside from their awesome DR...there are a number of reasons why they are not as good an option as Canon. I've listed them so many times now, I'm not going to again...however, I'm sure your reasons are the same as mine for preferring Canon. 

Your statement embodies the core frustration with Canon, though. Why the hell am I shooting Canon when there are other brands with more resolution? 

My question is: Why can't I have it all in a single brand? Why does everyone find it so "odd" that someone wants that? :-\


----------



## neuroanatomist (Sep 3, 2014)

*Re: EOS 7D Mark II & Photokina*



jrista said:


> My question is: Why can't I have it all in a single brand? Why does everyone find it so "odd" that someone wants that?



Wanting it isn't odd. I want free college educations for all my kids. I want a car that gets 200 mpg, seats 8 and has enough power and torque to pull a loaded trailer. I want to visit the International Space Station...next week. 

No...wanting isn't odd. But wanting something _unrealistic_..... 

Granted, Canon releasing a high-MP sensor with 13+ stops of DR is probably realistic from a technical standpoint. But technical feasibility isn't the main driver...the market is the driver. To date, the market has been showing them that their sensors "ain't broke" so Canon feels no need to "fix them". Wanting Canon to expend resources in an area their market research shows they don't need to..._that's_ where things start getting less realistic.


----------



## lo lite (Sep 3, 2014)

*Re: EOS 7D Mark II & Photokina*



jrista said:


> Are there any reasons why you wouldn't buy Nikon? Aside from their awesome DR...



jrista, you seem to be a one topic guy. All the post of you I read are basically the same. If this topic has such an importance for you why don't you do something about it like writing letters to Canon instead of annoying the folks here? Just an idea …


----------



## sarangiman (Sep 3, 2014)

*Re: EOS 7D Mark II & Photokina*



jrista said:


> Are there any reasons why you wouldn't buy Nikon? Aside from their awesome DR...there are a number of reasons why they are not as good an option as Canon. I've listed them so many times now, I'm not going to again...however, I'm sure your reasons are the same as mine for preferring Canon.
> 
> Your statement embodies the core frustration with Canon, though. Why the hell am I shooting Canon when there are other brands with more resolution?
> 
> My question is: Why can't I have it all in a single brand? Why does everyone find it so "odd" that someone wants that? :-\



We share the same sentiment here. Camera companies are far too slow to innovate and disrupt. Sony is at least trying, at least partially, if not mostly, because they literally *have* to in order to make a dent in the market.

That's at least partially why we can't have everything in one camera.

And I don't know that you can particularly blame them. The market itself looks like it's shrinking. And companies need to do what they need to do to survive. That said, from a consumer perspective, I can't help but be pleased when I see companies innovate for their customer base.

But a bigger reason - IMHO - is b/c they really can't predict all use-cases. And ideas propagate slowly within complex organizations. Which is why, eventually, whoever opens up their cameras and crowd-sources function/app-development will have a huge impact in this regard. I think, anyway.

Are there any reasons why I wouldn't buy Nikon? Not any compelling ones anymore. I guess I'd say: 
[list type=decimal]
[*]Lack of non-central cross-type AF points
[*]The wireless flash system w/ the 600EX-RT
[*]That wonderful new Canon 16-35 f/4L IS (I'm sure hoping that Sigma 14-24 rumor is true; I don't like the ergonomics of the Nikon 14-24 that makes practical use of filters impossible)
[/list]

Ultimately, though, those aren't compelling enough to overcome the poor DR, FPN, banding, lower resolution, and utter lack of any reasonable AF tracking capabilities in 3D (meaning, the X-Y 2D plane as well as the depth axis).

And before someone brings up how the DR evens out at high ISO - no it doesn't, not if you shoot in an 'ISO-less' manner where you can maintain somewhere near the full base ISO DR at higher ISOs simply by not allowing your ISO to float (assuming quantization error does not become a factor). But that's far too much to get into here. Incidentally, this type of shooting is exactly what you hounded me for doing when you de-railed that thread years ago where I compared the D800 to the 5DIII. About underexposing 5 stops & then pushing in post. Funny enough - that's exactly what I do right now in certain situations with my A7R in certain high DR scenes where I'm light limited b/c of the shutter speeds and/or aperture I wish to use. And it's likely to be the way cameras work in the future. Again, too much to get into here, but I'm guessing you know exactly what I'm referring to. As I said in my follow-up comment years later on that thread - underexposing 5 stops is nothing for some sensors these days. The only noise cost you pay is a tiny bit of quantization error (that's probably irrelevant) and mostly just the shot noise cost you'd pay anyway if you shot ISO 3200 (5 stops less exposure than ISO 100). Anyway.

Let me address that comment about AF tracking I made above. To be frank: I wish I'd tested Nikon's 3D AF tracking a long time ago. I use it in a bit of an unintuitive way - to avoid the focus issues arising from focus & recompose changing your plane of focus. Instead of moving the AF point using the antiquated joystick/D-pad method (far too slow), I let the camera automatically track the subject I initiate focus on using the center AF point. The only Canon camera that can even attempt this is the 1Dx, and even then it doesn't do it as well (in my tests) as the Nikon D800/D810/D4s - presumably b/c Nikon's been honing this for years. And then I have the added benefit that if the subject does happen to move while I recompose, the camera takes care of that as well. This did wonders for my baby photography, actually. I nailed shots focused on the eye of a wildly moving baby at f/1.4 - something I couldn't have dreamt of doing with my 5D3. Unless I stuck with a static AF point, of course, and manually recomposed to follow the eye/baby around such that the AF point was always over the subject of interest. 3D AF tracking obviates the need for this - allowing you to uncouple focus from the composition. 

That's huge, to me.

It literally opens up shooting possibilities for wedding photography that no Canon camera - save for the 1Dx - can even dream to attempt.

And the same hardware that enables this allows for spot-metering all over the frame, and face-detection metering. Again, only the 1Dx can attempt this, but many Nikon cameras do this with either their 2k or 91k pixel RGB sensor. Even the D7000 tracks across the frame surprisingly well, with its limited resolution (2k) RGB sensor. The 91k pixel sensors do it better, but it's admirable that a camera like the D5300 can even do this at all. Compare that to a Rebel that can't even attempt to, and even if it could, it'd be of limited utility with 9 AF points.

I've shot Canon since the film era, including the 5D, 5D2, and 5D3. And I can honestly tell you that for my type of shooting, switching to the Sony A7 series and the D810 has opened up shot opportunities for me that I just couldn't imagine with my Canon cameras.

YMMV.


----------



## sarangiman (Sep 3, 2014)

*Re: EOS 7D Mark II & Photokina*

Oh, and jrista:

I meant to respond to your comment at some point about how you shoot at ISO 400 and average images to help with Canon DR. Honestly, at first glance I thought it was quite funny, but I did the math and you were on to something there. I'll see if I can write out the actual math to show where that method benefits, and where it doesn't.

But in the meantime, I just wanted to say:

Some people will say that extra DR doesn't help landscape photographers that much b/c the shot noise in the shadows makes shadows look like higher ISO shots. So you should HDR anyway. Ok, valid point; just that with Canon you have this problem *on top of* extra noise due to read noise.

But I'd argue that even in such situations, the higher DR sensor still helps dramatically. Why? B/c you don't actually have to merge different exposures to get HDR. You can just shoot a bunch of the *same* exposures - since almost everything is more likely to be above the incredibly low noise floor - then average them, then post-process to taste. This avoids the issue of masking/HDR software merging different exposures, where dark/bright boundaries can cause issues in the algorithms as to which image to use pixels from. Of course, you may still have to mask for selective brightening/darkening, but this is much easier - to me anyway - than merging different exposures for HDR.

With Canon & this method, you'd be fighting read noise on top of shot noise, requiring you to average many more images. Or increase the exposure to get some of the darkest subjects in your scene above the noise floor to begin with. 

Make sense?


----------



## Don Haines (Sep 3, 2014)

*Re: EOS 7D Mark II & Photokina*



neuroanatomist said:


> jrista said:
> 
> 
> > My question is: Why can't I have it all in a single brand? Why does everyone find it so "odd" that someone wants that?
> ...


I think the truth is somewhere in the middle.

If Canon wanted to, they could plop down a multi-million dollar stack of money and buy a new fabrication line. We know that they have been designing sensors in lab that use finer lithography, and it isn't that hard to move the A/D onto the sensor...

We also know that Canon already has a finer fabrication line that is seeing less demand.

We STRONGLY suspect that the 70D's sensor is made on the finer fabrication line.

We also know that it costs more to run 2 fabrication lines than one....

My bet is that Canon is in the process of moving all sensors over to the finer fabrication line and that in the next year or two we will see an update of all their cameras, and then the 500nM line will be shut down. When transferring the designs over, it is the logical time to shuffle things around to attack the noise problem.

The 7D2 will be a big clue as to if this is happening


----------



## sarangiman (Sep 3, 2014)

*Re: EOS 7D Mark II & Photokina*

Don's post reminds me: Canon's Dual-Pixel AF is one of the most exciting technologies I've seen recently. If this tech grows and is implemented correctly, it could really revolutionize AF, in my opinion. It could probably do away with AF microadjustment, while increasing precision of wide aperture/shallow-DOF shots. On-sensor PDAF will have to find a way around the low SNR of split photodiodes or masked pixels, but there are some obvious ways around this.

I do hope Canon invests in this tech.


----------



## sarangiman (Sep 3, 2014)

*Re: EOS 7D Mark II & Photokina*

There's another arena Canon may do better in w/ the 5D3/1Dx AF module. There are 5 high-precision dual-cross-type sensors down the middle. I wonder if these actually have demonstrably higher precision for wide aperture shooting compared to Nikon's central AF points. To my knowledge, no one's tested this rigorously.

I've also noticed some body/lens combos where there'd by systematic back/front-focus based on which direction the focus element was moving. With both Canon and Nikon systems. I wish someone would test this stuff in a systematic manner so we could see where these problems do or do not exist.

Ultimately, though, the inability to track subjects in the X-Y plane have led to many more missed shots with my 5D3 compared to (my limited shooting thus far with) the D810, so that matters to me.


----------



## jrista (Sep 3, 2014)

*Re: EOS 7D Mark II & Photokina*



sarangiman said:



> Oh, and jrista:
> 
> I meant to respond to your comment at some point about how you shoot at ISO 400 and average images to help with Canon DR. Honestly, at first glance I thought it was quite funny, but I did the math and you were on to something there. I'll see if I can write out the actual math to show where that method benefits, and where it doesn't.
> 
> ...



Makes total sense. In the past, I'd thought that the 5D III's read noise was much more random than it is. That was what people were raving about back when it was first released. Now that I own it, it's clear to me that the read noise is still heavily banded, and some of that banding is fixed. The problem with averaging fixed information is it strengthens, where averaging random information effectively bleeds it out. So I totally agree, the clean, random photon shot noise that occurs way down into the deep shadows is far more effective for averaging multiple shots together than with a Canon camera.

I'm still not quite sure of the "ISO-less" nature of the Exmor. I know that's what it's generally called on DPR, but if that was the case, why does Exmor still employ per-pixel amplifiers? There has to be a benefit to amplifying the RAW signal at the pixel, before read, if Exmor is still doing that. Otherwise, the entire thing would be 100% digital, and all ISO settings would be achieved as you say...simply by digitally boosting ISO 100 shots. I agree that shadow detail and color fidelity in a D800 is better, by far as I now see, than a 5D III...however to use it in a true ISO-less manner. You have to be losing color fidelity in the highlights at some point, no? 

Regarding the 3D AF...I knew about it's capabilities. I'm curious though. Whenever I've played with Nikon cameras in a store, the AF points always seemed rather tightly clustered in the center of the frame. The point spread seems rather low, in other words. One of the things that is nice about Canon's 61pt AF system is the very wide point spread...I can AF way out well into the midframe, even on a full frame camera. Is that still the case with Nikon? Are their AF points still tightly clustered and small? 

There is also the fact that the 61pt AF system has a ton of cross-type points, and the five double-cross type in the center. I don't know how 3D AF would affect bird and wildlife photography, I'd have to give it a try. I do know that having high precision AF points, and having cross type points spread throughout the entire frame, is a huge bonus over what the 7D offered.


----------



## sarangiman (Sep 3, 2014)

*Re: EOS 7D Mark II & Photokina*



jrista said:


> Makes total sense. In the past, I'd thought that the 5D III's read noise was much more random than it is. That was what people were raving about back when it was first released. Now that I own it, it's clear to me that the read noise is still heavily banded, and some of that banding is fixed. The problem with averaging fixed information is it strengthens, where averaging random information effectively bleeds it out. So I totally agree, the clean, random photon shot noise that occurs way down into the deep shadows is far more effective for averaging multiple shots together than with a Canon camera.



Glad you see that now. But even if it were perfectly random, you'd still have to average many, many more Canon shots to use shadows that you could use from a D800/810 or Sony A7R without any averaging whatsoever. And the nice thing about shot noise in shadows is that, well, our visual system is more tolerant to them b/c they're shadows and not as bright and visible as midtones and highlights. So I'll often put up with the shadows after a huge lift of a D810 file, simply b/c the shot noise is nowhere near as image detail killing as the read noise from my 5D shots.



jrista said:


> I'm still not quite sure of the "ISO-less" nature of the Exmor. I know that's what it's generally called on DPR, but if that was the case, why does Exmor still employ per-pixel amplifiers? There has to be a benefit to amplifying the RAW signal at the pixel, before read, if Exmor is still doing that. Otherwise, the entire thing would be 100% digital, and all ISO settings would be achieved as you say...simply by digitally boosting ISO 100 shots. I agree that shadow detail and color fidelity in a D800 is better, by far as I now see, than a 5D III...however to use it in a true ISO-less manner. You have to be losing color fidelity in the highlights at some point, no?



In the highlights? Did you mean shadows?

There could be a number of answers to this question, and it's probably a combination of things. First of all, your hardware really does have to be 'ISO-less'. This means almost zero downstream read noise. We're not there yet, but we're quite close. Second, there's the issue of ADC bit-depth, FWC, and quantization error. There's a subtle interplay between pixel pitch, FWC, and ADC bit-depth that can lead to increased quantization error if you don't do any amplification above base ISO levels. Too much to go into here, but I bet you can think through it.

Point is: there are still some hardware limitations. 

But perhaps more importantly, re-hauling the idea of ISO (which is really still a holdover from the days of film) is a big step, and combining that with exposing for the highlights, ETTR, etc. is a very different way of shooting. And camera manufacturers radically innovating and disrupting is not an every-day occurrence.

Furthermore, I wonder how many people at the camera companies are fully aware of just how ISO-less their cameras are. You need to do some sophisticated analysis (photon transfer) to really get at this, but it's possible to rigorously quantitate benefits vs. cost. Now, how many of those that are aware & have done this also understand the photographic implications? And what subset of those can actually convince the rest of the people that need convincing to implement this type of feature in the next camera? And who can do it in a clever-enough way that it appears pretty transparent to the end user who, ideally, should only experience the benefits rather than be forced to understand a new way of shooting...?

To do it absolutely properly, I think there'd have to be some significant changes to the entire way the camera meters and then displays the scene. But I won't go into that here. Suffice it to say there'd have to be a number of algorithmic, as well as UI, tweaks. And how often do we see manufacturers make radical changes? The point is: there are already energy barriers to doing this, and these companies tend to be rather slow to begin with.

But someone should, and someone will. In the meantime, there are those of us that just use the camera in very unintuitive ways to still get the benefits of this type of shooting.



jrista said:


> Regarding the 3D AF...I knew about it's capabilities. I'm curious though. Whenever I've played with Nikon cameras in a store, the AF points always seemed rather tightly clustered in the center of the frame. The point spread seems rather low, in other words. One of the things that is nice about Canon's 61pt AF system is the very wide point spread...I can AF way out well into the midframe, even on a full frame camera. Is that still the case with Nikon? Are their AF points still tightly clustered and small?



No. Here's a side-by-side showing the spread of AF points between the Nikon D800 and Canon 5DIII:







The only advantages I see with the Canon AF spread are the 4 extra corner points (upper/lower right, upper/lower left), and the higher density.



jrista said:


> There is also the fact that the 61pt AF system has a ton of cross-type points, and the five double-cross type in the center. I don't know how 3D AF would affect bird and wildlife photography, I'd have to give it a try. I do know that having high precision AF points, and having cross type points spread throughout the entire frame, is a huge bonus over what the 7D offered.



Yes, as I mentioned in my previous posts. Actually, the 7D had all cross-type points, just not with the spread of the 5DIII/1Dx. The lack of cross-type points does sometimes cause hunting when focusing on horizontal lines (e.g. eyes/eyebrows) in _portrait_ orientation. You can sometimes combat this by rotating your composition slightly in portrait orientation (or rotate slightly when acquiring AF). It's certainly not ideal, but it can help.

And, remember, the cross-type points were literally the only reason I chose the Canon 5DIII over the D800 years ago (actually I also disliked the grip, the D-pad, the LCD, and the Live View implementation - all of which have been fixed in the D810). So I'm with you there. Recently, armed with a very good sense of my AF hit-rate with micro-adjusted fast primes at f/1.4 with the 5DIII (from shooting with it extensively over the past few years), I decided to give the D810 a fair chance with a 35mm f/1.4 lens. My hit-rate actually went up, and that with a 36MP sensor which has a much tighter tolerance for focus error. Furthermore, it enabled a type of shooting I literally couldn't do with the 5DIII, tracking subjects (usually the eye - I like very close-up, off-center comps with the 35/1.4) in three, not one, dimensions. And I would often use well off-center AF points. Yes in tough lighting situations in portrait orientation the outer points would hunt on horizontal detail - the main reason I dismissed the D800 years ago. But when I weighed that against the hit rate at f/1.4 otherwise, and the tracking, it really put the lack of cross-type AF in perspective.

This is not at all meant to be an excuse for Nikon (and most brands') lack of cross-type AF sensors well off-center. It's difficult to design, if I understand correctly, and I applaud Canon for pioneering this. I really hope Nikon (and Sony in their SLT line, for that matter) follow suit. 

Now, when I'd previously tried 3D AF tracking, I don't remember being *this* impressed with it. The speed of the tracking is so fast and steady sometimes that my first reaction was to wonder if the camera was using its accelerometer/sensors to along with information about the focal length of the lens to move the AF point. It sometimes feels *that* responsive. Of course, that was easily disproved by having the stationary camera track a fast moving subject. It's possible that a combination of the improved processing speed, further optimized algorithms, and the 91k sensor (as opposed to the 2k sensor in some other models) combined to make this experience this time so impressive. It's hard to say, though, b/c the D800 and D4s also track very well, and without a more objective, rigorous test... I can't say they're any worse or better than the D810. But they were all better at shifting the AF point to stay on the initial subject than the 1Dx _in my tests thus far_ - where the 1Dx would typically play catch-up or lose the subject over time altogether. That's not to say the 1Dx can't/won't perform just as well or better in other scenarios, but it's demonstrably slower than either the D4s or the D800/810 at sticking to the original subject while constantly recomposing the scene by moving the camera. Not that I would ever even consider the 1Dx b/c of its heft, as well as its utterly inane implementation of EC in M mode w/ Auto ISO. Then again, at least it's the one Canon DSLR to have what most other modern ILCs have... what's ironic is that Canon DSLRs need EC in M mode with Auto ISO the most - simply b/c it's more critical to nail ISO on Canon DSLRs to avoid downstream read noise than it is for, say, an A7 or D800 where you can mistakenly leave the camera at ISO 100 in M mode and then just brighten in post (shooting Raw). In other words, you generally want the ISO amplification on Canon DSLRs to be the highest level that doesn't clip highlights so as to maximize the chances of any image data being well above the noise floor. 

But again, I digress 

All that said, I really would like to do a controlled study to see if Canon's dual cross-type high precision points actually give better precision (repeatability) under various lighting levels compared to the center points on the D810. As well as comprehensive tests on AF precision with various lenses on these systems. Basically, objectify tests that these days too many people offer subjective opinions on...


----------



## sarangiman (Sep 3, 2014)

*Re: EOS 7D Mark II & Photokina*

Also, I wanted to provide a real-world example of when 'ISO-less' shooting can help to retain the base ISO dynamic range of the camera at higher ISOs.

Below is a shot of the setting sun taken on a lake in Cambodia on a rough, rocking motorboat. Taken with a *Sony A7R with Canon 70-200mm f/4L (non-IS)* + 1.4x II TC + Metabones Smart Adapter III*.






Given the constant motion of the boat & the lack of IS on the lens, and the focal length of 280mm, I dared not use a shutter speed below 1/250s. I wanted an aperture of f/11 to guarantee focus on the boats all the way to the sun. For a proper midtone exposure, this meant I had to use ISO 1600. But instead I used ISO 100, so here's what the shot looked like SOOC:






I then selectively applied what amounted to a 4 EV push in the shadows, and varying levels of exposure boost in others. Importantly, not allowing the sun to blow out. This allowed me to capture a rather high dynamic range scene even at a high ISO setting - albeit only a 'simulated' one, if you will. Meaning I didn't actually use a high ISO, although the focal plane exposure was set to something more along the lines of what the camera would've used at a higher ISO (you're probably beginning to see why the ISO term itself is becoming a source of confusion when shooting in such an odd manner, as I was alluding to in my previous post).

My take home point -- to those who say you don't care about base ISO DR b/c higher ISO DR matters more to you, I say: here's an example where you can approach the base ISO DR of the camera _at higher ISOs_, albeit only if you shoot in this very strange, seemingly broken manner  But there's a bigger point here - the low downstream read noise that enables high base ISO DR _also allows for higher DR at all ISOs if you shoot in this 'ISO-less' manner or if, in the future, manufacturers tune their cameras to work in such an 'ISO-less manner'._

In other words, jrista, here's an example where underexposing by 4 EV (by lowering the ISO 4 EV in M mode) was not only a reasonable thing to do, but the *right* thing to do to save the red channels sampling the sun from clipping.

Some fun math to prove my point better:
Loading the RAW file in RawDigger, there's a 9.5 EV difference between the red channel in the sun vs. in some of the shadows of the people on the boat. Now, let's say I'd gone ahead and used ISO 1600 and picked an exposure such that the sun was just under the clipping point. The A7R & 5DIII both have a DR of ~10 EV (using SNR=1 as the lower cutoff) at ISO 1600, so perhaps those 9.5 EV would have, technically, fit into the DR capabilities of both cameras. But that would've placed the shadows at SNR=1. That's unusable to most people. But at ISO 100, the A7R has ~13 EV pixel-level DR. The red channel of the sun is at about 1 stop below clipping in this shot**, which places the red channel of some of those shadows ~10.5 EV below the clipping point of this camera, which should still be comfortably (2.5 EV) above the noise floor given the 13 EV of DR. If I'd done the same with a 5DIII - which has a pixel-level DR of ~11 - some of my shadows would've been 0.5 EV above the noise floor (of SNR=1). Definitely not where you want to be. 

The difference in performance only becomes even more marked with the extra DR of the D810 at ISO 64.

To sum it up again:
The camera with high base ISO DR can still give you high DR in situations that'd typically demand use of high ISOs. Whereas the camera with equivalent high ISO DR but poor base ISO DR would not give you this option at all. 



*I gave up on the f/4L IS lens b/c 3 copies I tested would, every now and then, render 1/4 to 1/3 of one side of the image soft... the non-IS is much better behaved in this regard. Also I'm not the first to report this: http://diglloyd.com/articles/LensAndCameraIssues/BrandNewBlur-Canon70_200f4L.html. 

**So, yes, I could've boosted exposure more at the time of exposure. But, (1) I was already constrained by the shutter speed & aperture I felt appropriate for that situation, and (2) while yes I could've gotten away with ISO 200 here, I'm not a computer hard-wired in to my camera, so the best gauge I had of the ISO to use was the histogram on the camera - which showed me approaching clipping. And, to be honest, sometimes when I don't want to think too much about the technicalities and want to focus on the moment instead, I'll just set shutter speed & aperture on my A7R for (1) artistic intent and constraints, and (2) to avoid clipping, then simply leave ISO at 100 and raise selectively in post. For high DR scenes anyway. Otherwise I'll keep the camera in Auto ISO mode & use negative EC to avoid highlight clipping. The only cost I *sometimes potentially* pay is quantization error for deep deep shadows at ISO 100, and maybe some tiny amount of downstream read noise influence. But even for the former, I think it's irrelevant for most situations, as only signals lower than 16 photoelectrons have their random fluctuations (shot noise, which'd be ±4 photoelectrons here) represented by less than 1 digital unit/increment at ISO 100. I think I've probably lost any reader interest I still had at this point so...


----------



## AmselAdans (Sep 3, 2014)

*Re: EOS 7D Mark II & Photokina*



sarangiman said:


> *snap*



Inspiring post, I never thought about this approach.
But isn't there the high risk of color banding?

Assume you have a 10 bit color channel encoding, giving you 1024 shades of each channel (for this example, it doesn't mind whether its 8, 10, 12 or 14 bit..)
The people on board are quite dark in the original shot, so the color information, e.g., of the blue channel may be concentrated in an interval of [0..140]. When then compensating the underexposure, you expand this interval, as the guys now feature lighter shades of blue in their shirts. From some quick Photoshop color grabbing in your picutres, the interval would now approximately be [0..500].
Thus, this will have a posterization effect at a certain degree. You definitively lose color information by this way.

The tradeoff would be interesting between this color posterization but low ISO setting and no posterization but noise from higher ISO settings.


----------



## sarangiman (Sep 3, 2014)

*Re: EOS 7D Mark II & Photokina*



AmselAdans said:


> Inspiring post, I never thought about this approach.



Thanks, and hey jrista - there you go. A data point for 'how many people have actually thought of & tested the validity of this approach?' 



AmselAdans said:


> But isn't there the high risk of color banding?
> 
> Assume you have a 10 bit color channel encoding, giving you 1024 shades of each channel (for this example, it doesn't mind whether its 8, 10, 12 or 14 bit..)
> The people on board are quite dark in the original shot, so the color information, e.g., of the blue channel may be concentrated in an interval of [0..140]. When then compensating the underexposure, you expand this interval, as the guys now feature lighter shades of blue in their shirts. From some quick Photoshop color grabbing in your picutres, the interval would now approximately be [0..500].
> ...



First of all, it's a bit of a fallacy to think that noise comes from higher ISO settings. In this case, holding shutter speed & aperture constant, increasing the ISO would have potentially led to *lower*, not higher, noise. The higher noise from higher ISO settings comes from the typically shorter exposures people use at higher ISO settings. But the type of shooting I was doing - all of that goes out the window. You determine the shutter speed/aperture (the focal plane exposure), and then you choose the highest ISO that doesn't clip highlights. My bigger point was that for some cameras, it's not even critical that you choose this 'highest ISO' at all - just keep it near base and adjust exposure in post-processing.

Now, you're worried about expanding the intervals in low tones by raising the exposure in post. But you should be just as worried about raising those tones via ISO amplification in the camera! Because those low, dark tones also would've had very low, 'granular' signals at the level of the sensor - prior to ISO amplification.

The only difference is that the former (raising in post) runs the risk of some loss of information compared to the latter if your ADC bit-depth is not adequate enough at base ISO to represent the noise in the signal accurately. That's why in my second footnote I brought up the topic of quantization error and making sure that the random fluctuation in the signal (resulting mostly, if not almost exclusively, from shot/photon noise in high performance sensors) are accurately represented in the RAW file. You should be fine as long as the standard deviation of any given pixel signal is represented by at least 1 digital unit/increment. This does fall apart (if I did my math right) for signals lower than 16 or so at ISO 100 for the A7R. But, those are very, very low signals. And I'm still not convinced it actually has a significant, discernible effect.

Fundamental to understanding all this is realizing that when you sample a signal of 4 photoelectrons, the best SNR you can get is sqrt(4) = 2. This is b/c the standard deviation of that signal due to statistical/photon/shot noise (http://en.wikipedia.org/wiki/Shot_noise) is equal to the sqrt of the signal, or 2, in this case. This noise can actually provide some dithering effect, so accurately recording tones generating 3, 4, or 5 photoelectrons is less about actually accurately recording those as 3, 4, and 5 and more about making sure you don't drastically undersample shot noise (which has a dithering effect). In other words, instead of worrying about recording increments of 1 in the digital file, you should worry about recording the increments of the fluctuations of that signal. And for a signal of 4, that means accurately representing a fluctuation of 2 (sqrt(4)), not 1. Of course, you'll probably always be better off with a higher bit-depth ADC (barring other associated deleterious effects related to system design); I'm just saying I don't know how much it matters in most shooting scenarios. 

In the words of Emil Martinec, who did a beautiful study/treatise on all of this: "Posterization becomes apparent when the quantization step sufficiently exceeds the width of the noise, the random jumps in tonality due to the noise are no longer able to dither the discrete jumps due to quantization."

Read more about this here: http://theory.uchicago.edu/~ejm/pix/20d/tests/noise/noise-p3.html#bitdepth

Remember that your digital file is trying to represent a quantized signal (based on # of photoelectrons generated during exposure at any given pixel). As long as your amplification and bit-depth are set up so that 1 digital increment in your RAW file represents 1 or less photoelectrons, you should be pretty accurately representing the original signal. When 1 digital increment represents more than 1 photoelectron (which can be the case for base ISO on full-frame sensors), you *could* run into tonality issues, but you often don't _because_ of shot noise that leads to random fluctuations in the signal that amount to sqrt(signal). Here, it becomes more important that you digitally accurately represent the fluctuations in the signal (noise) rather than the quantized steps in the signal itself. This essentially lessens the need for very high bit-depth ADCs, save for in some outlier use-cases.

Apologies in advance if that made absolutely no sense...


----------



## sarangiman (Sep 3, 2014)

*Re: EOS 7D Mark II & Photokina*

Let me reiterate:

There might still be *some* advantages even for the most 'ISO-less' cameras today to using, say, ISO 400 amplification vs. ISO 100 for the darkest of signals. Because there's still some finite read noise in the signal chain. However, it may be academic for many.

And for very very high ISO applications, where every fraction of an electron in noise counts, you'll see benefits to hardware-level ISO amplification. Again, b/c of that finite read noise that is still introduced by the signal processing. Or b/c of other things like conversion gain optimizations (e.g. what's suspected to be the case in the A7S). And when you're trying to make an image with 40-50 photoelectrons of less per pixel... every electron of noise saved counts.


----------



## jrista (Sep 3, 2014)

*Re: EOS 7D Mark II & Photokina*



sarangiman said:


> Let me reiterate:
> 
> There might still be *some* advantages even for the most 'ISO-less' cameras today to using, say, ISO 400 amplification vs. ISO 100 for the darkest of signals. Because there's still some finite read noise in the signal chain. However, it may be academic for many.
> 
> And for very very high ISO applications, where every fraction of an electron in noise counts, you'll see benefits to hardware-level ISO amplification. Again, b/c of that finite read noise that is still introduced by the signal processing. Or b/c of other things like conversion gain optimizations (e.g. what's suspected to be the case in the A7S). And when you're trying to make an image with 40-50 photoelectrons of less per pixel... every electron of noise saved counts.



I agree with this. In this case, this is where Canon cameras are currently superior (at least, to most...I think the D810 is starting to change this). At higher ISO, most Exmor cameras still have ~3e- RN, even more. Canon sensors, on the other hand, drop to 2e- and below at the higher ISO settings, dropping to as little as ~1.3e- on some cameras at very high ISO. Those savings in RN are what give Canon's 1D X, 6D (and even to a small degree, the 5D III) the dynamic range/SNR edge at high ISO. The D810 ultimately drops to 1.3e- at it's highest ISO setting, but it still doesn't manage to eek out more DR than the 5D III, and certainly not as much as the 6D and 1D X.

However, with the D810, Nikon seems to have introduced a bias offset, and they now have a roughly linear falloff in read noise compared to the flat RN curve of the D810. I think that further enhanced the value of using higher ISO settings, vs. using the camera "ISO-less", for anything above ISO 400. 

As far as ISO-less applications go, I still think that is currently only the realm of low ISO/bright light shooting. You can underexpose to preserve the highlights, and recover the midtones and shadows. That only really works because 3-5e- RN is trivial compared to 50ke- to 80ke- maximum signal, and even 25ke- to 40ke- midtone signal. I don't think quantization noise is really much of an issue either...that would only really cause a bit of posterization in the really deep shadows...but your unlikely to be lifting them enough to actually see that...not unless you have a LOT of shadow detail to recover.


----------



## sarangiman (Sep 4, 2014)

*Re: EOS 7D Mark II & Photokina*



jrista said:


> I agree with this. In this case, this is where Canon cameras are currently superior (at least, to most...I think the D810 is starting to change this). At higher ISO, most Exmor cameras still have ~3e- RN, even more. Canon sensors, on the other hand, drop to 2e- and below at the higher ISO settings, dropping to as little as ~1.3e- on some cameras at very high ISO. Those savings in RN are what give Canon's 1D X, 6D (and even to a small degree, the 5D III) the dynamic range/SNR edge at high ISO.



*No*. And I wish these myths weren't propagated with a resilient persistence as readily as they are on forums. First of all, if you want to talk about 'superior', talk about the Sony A7S and its _sub_ 1 electron read noise.

More importantly, I'd treat those read noise numbers on sensorgen a little more softly. Don't get me wrong - I do value sensorgen - but do consider there are no error bars or stdev quoted. Second, it's not just about (upstream) read noise here. You're quoting fractions of electrons differences, yet ignoring QE differences?

The reality is: there _are_ differences, but they're more in-line with generations of tech; beyond that you're splitting hairs at best. Furthermore, simply quoting the min read noise ignores # of pixels, which matters for sensible, normalized comparisons.

Fortunately, we can look at some test shots taken at the same focal plane exposures:

*D810 vs 6D vs 1Dx vs D800E*
http://tinyurl.com/n3cke3v

Are those differences - at ISO 12,800 no less - really worth talking about? I guess that's up to you, and if it were me I'd rank performance D810 = 1Dx > 6D > D800E*. I'd also remind you that the D810 is performing on par with the 1Dx despite having twice as many pixels! Yes the D800E is performing slightly worse, but at more reasonable ISOs of 3200 and below, it's a wash.

And this whole 'Canon cameras are superior' attitude... it's like brand religion. And it's demonstrably false. Now let's take a look at some other cameras, including the 5DIII which you think is somehow better than Exmor:

*D4s vs A7R vs 5DIII vs D610*
http://tinyurl.com/kd7vze3

Pretty marginal differences between the 5DIII, the A7R (Exmor), and the D610. Nikon D4s beats all of them, though. And, actually, at higher ISOs the A7R - after removal of the magenta tint in shadows - perhaps even slightly _outperforms_ the 5DIII in normalized comparisons: http://tinyurl.com/k2dam52. At any rate, it certainly doesn't _underperform_ compared to the 5DIII.

So where is this Canon 'superiority' and 5DIII's 'small degree [of an]... edge' at high ISO?

While we're at it, let's look at some APS-C cameras:

*Canon 70D vs Nikon D3300 vs Nikon D7100 vs. Canon Rebel T5i*
http://tinyurl.com/orncyb8

The Nikon D7100 (Toshiba sensor) outperforms all of those cameras, and the Nikon D3300 performs better than both the Canon cameras _despite 1/3 EV less focal plane exposure _(all other cameras received the same focal plane exposure).

I could go on, but I think you get my point...



jrista said:


> The D810 ultimately drops to 1.3e- at it's highest ISO setting, but it still doesn't manage to eek out more DR than the 5D III, and certainly not as much as the 6D and 1D X.



Why are we still talking about high ISO DR disadvantage for the low (downstream) read noise camera (D810) when I clearly demonstrated in one of my previous posts that you can get demonstrably more DR at high ISO by underexposing & boosting exposure selectively - something you're less able to do with a Canon DSLR?

Furthermore, according to that _site-no-one-speaks-of-here-but-who's-data-the-site-you-quoted-numbers-from-derives-its-data-from_, there's *no difference* in normalized DR between the D810 and the 5DIII at high ISOs.



jrista said:


> However, with the D810, Nikon seems to have introduced a bias offset, and they now have a roughly linear falloff in read noise compared to the flat RN curve of the D810. I think that further enhanced the value of using higher ISO settings, vs. using the camera "ISO-less", for anything above ISO 400.



Since you brought it up: I'm a little confused by sensorgen's numbers for the D810, as they disagree with DxO's. Sensorgen gives the D810 lower pixel-level DR than the D800/E, whereas DxO clearly shows the opposite. 

As for the value of higher ISO vs. shooting 'ISO-less' (to some degree anyway), that depends on what you care about. Comparing ISO 1600 vs ISO 400 + 2EV (same shutter speed/aperture), the tradeoff is between (1) a couple electrons more noise per-pixel, and (2) two whole stops of DR.

I personally, generally, prefer the flexibility of option (2). But now we're veering off the main point of our discussion, which is that the absence of downstream read noise (high base ISO DR) opens up possibilities otherwise impossible to achieve. And this doesn't come at some high ISO performance cost (compared to Canon). It *didn't* back when the D800 and 5DIII were introduced, and it *doesn't* now. 

And it's a tenuous thread - if not utterly wrong in some cases - to claim that somehow Canon sensors in general are 'superior' to all others with respect to ISO performance. Compared to Exmor or no Exmor.

*The Nikon files have a bit more magenta in blacks at the highest ISOs, though this could possibly be from ACR's 'Shadows Tint' calibration.


----------



## jrista (Sep 4, 2014)

*Re: EOS 7D Mark II & Photokina*



sarangiman said:


> jrista said:
> 
> 
> > I agree with this. In this case, this is where Canon cameras are currently superior (at least, to most...I think the D810 is starting to change this). At higher ISO, most Exmor cameras still have ~3e- RN, even more. Canon sensors, on the other hand, drop to 2e- and below at the higher ISO settings, dropping to as little as ~1.3e- on some cameras at very high ISO. Those savings in RN are what give Canon's 1D X, 6D (and even to a small degree, the 5D III) the dynamic range/SNR edge at high ISO.
> ...



Whoa. Slow down buddy.  First off, I hadn't checked the A7s on Sensorgen. I agree, it has vastly superior RN at high ISO. Pretty amazing, actually. That said, I wouldn't call this a "myth"...there is a Q.E. difference at high ISO, however DESPITE that, the higher RN of the D800/D600/etc. reduces their dynamic range a bit at higher ISO. 

The D4 and 1D X (and to a degree the 6D), as well as the A7s all enjoy a meaningful improvement to DR at very high ISO settings thanks to their low RN. It was specifically the increase in DR that I think makes these sensors superior at high ISO. I think the benefit of smaller pixels from a resolution standpoint is quickly lost once you start talking about the highly photon shot noise dominated signals at ISO 6400 and up (and maybe even ISO 3200).

This is one of the reasons I think a multi-layered sensor, vs. a bayer array, with the ability to dynamically bin pixels 2x2 and maybe even 3x3 as you increase ISO would be pretty awesome. The sparseness of the signal at really high ISO definitely increases noise, so the value of pixel count starts to diminish rapidly. Bigger pixels become increasingly valuable. That's why I think the 1D X and 5D III (and D4 and A7s) have a nice edge over the D800 and D600...they all have bigger pixels.




sarangiman said:


> More importantly, I'd treat those read noise numbers on sensorgen a little more softly. Don't get me wrong - I do value sensorgen - but do consider there are no error bars or stdev quoted. Second, it's not just about (upstream) read noise here. You're quoting fractions of electrons differences, yet ignoring QE differences?
> 
> The reality is: there _are_ differences, but they're more in-line with generations of tech; beyond that you're splitting hairs at best. Furthermore, simply quoting the min read noise ignores # of pixels, which matters for sensible, normalized comparisons.



It may be slitting hairs. The differences are indeed small, not large as they are at low ISO. However some of these sensors DO enjoy as much as a stop or so additional DR at high ISO over the D800, D600, and many of Sony's cameras. As I said, that seems to be changing with the D810 (and apparently the A7s).

As I mentioned, I think the value of small pixels quickly diminishes once were talking about ISO 6400 or 12800 or higher...then I think the read noise levels become critical.




sarangiman said:


> Fortunately, we can look at some test shots taken at the same focal plane exposures:
> 
> *D810 vs 6D vs 1Dx vs D800E*
> http://tinyurl.com/n3cke3v
> ...



Sure, I get the point. I've made the point several times myself...sensitivity is primarily a factor of total sensor area, not pixel size. The primary benefit of smaller pixel size is resolving power, not sensitivity. I think all the DPR links above demonstrate that point excellently. All of the APS-C samples have visibly more noise than the FF samples...and, you are right, there are only small visible differences between the FF sensor samples.

To be honest, the only real differences I can see are the differences on underlying tint. Some are redder, some are greener...and as you noted, the A7r seems to have a bit of a magenta tint. An excellent normalized comparison. I am curious, however, how each of those files handles exposure pushing and pulling, and color tweaking, in post. That is ultimately what I personally am most concerned about...in the end, how the images look is really the result of your processing. Does that magenta tint in the A7r clean up well, or is it difficult to clean up? Which ones handle a little bit of shadow recovery better?

There may simply not be an objective answer to those kinds of questions, simply because it's not really tested for. However, to the editing latitude end...your technique, the ISO-less technique, may really be the answer. I would have to experiment. If your underexposing by five stops then lifting by five stops, as though you shot at an ISO setting five stops higher...is there any actual benefit in improved DR? If you are not using the upper five stops that ISO 400 allows, then the primary difference between doing that...and shooting at 12800 is going to be the read noise levels. If it's 3e- at ISO 400 -5EV, and 1.6e- at ISO 12800, so long as your not clipping your highlights...wouldn't shooting at ISO 12800 directly be better? (Maybe I am misunderstanding your ISO-less technique...anyway, this is an honest question...I'd like to know what the real benefit of shooting ISO 400 -5EV and lifting in post is, given the RN differences.)



sarangiman said:


> jrista said:
> 
> 
> > The D810 ultimately drops to 1.3e- at it's highest ISO setting, but it still doesn't manage to eek out more DR than the 5D III, and certainly not as much as the 6D and 1D X.
> ...



I think I need to see an example of the ISO-less technique to understand the benefits of -5EV+selective boost, vs. just shooting at an ISO five stops higher.

As for sensorgen...I prefer the data they provide as it's UNcooked DXO data. DXO cooks their numbers when they package them up into their neat little reports. DXO has changed how they cook things behind the scenes at times, and a lot of it is black box...so I don't really trust it. I prefer raw, untainted measurements...which I think sensorgen provides. I agree, they could be more complete. SDtevs and the like would be very useful.

As for the D810 vs. 5D III at high ISO, if you compute the total amount of light gathered by the sensor at ISO 12800, the D810 actually does end up pulling ahead;

7380px*4920px*387e-/px = 14,074,663,680e-
5760px*3840px*526e-/px = 11,634,278,400e-

Per-pixel DR is lower on the D810, so you would clip the signal faster...however, if we applied your ISO-less technique, that really wouldn't be a problem. That's usually my greatest concern at really high ISO...clipping the signal, and having enough DR to reproduce good color fidelity and reduce noise. At these high ISO settings, the differences between cameras may boil down to 1/3rd of a stop...but, I think that 1/3rd of a stop can be and is valuable. 



sarangiman said:


> jrista said:
> 
> 
> > However, with the D810, Nikon seems to have introduced a bias offset, and they now have a roughly linear falloff in read noise compared to the flat RN curve of the D810. I think that further enhanced the value of using higher ISO settings, vs. using the camera "ISO-less", for anything above ISO 400.
> ...



The problem with DXO is we simply don't know exactly how they derive their chart numbers. That's one of the things I like about Sensorgen...it's just a raw data dump. Granted, that leaves it up to the reader to interpret, but...at least there isn't any special weighting or unknown mathematical formulas applied. 

I suspect normalization plays a role in the differences, as I don't think any information on sensorgen is based on normalized results. 



sarangiman said:


> As for the value of higher ISO vs. shooting 'ISO-less' (to some degree anyway), that depends on what you care about. Comparing ISO 1600 vs ISO 400 + 2EV (same shutter speed/aperture), the tradeoff is between (1) a couple electrons more noise per-pixel, and (2) two whole stops of DR.



I understand that. However, you have to actually make use of the extra DR. Underexposing at a lower ISO and boosting can avoid highlight clipping, and that is one of the primary concerns about shooting at high ISO. However, if you deal with ETTR properly, or use something like UniWB, the chances of clipping at any ISO are low. Then, the reduction in read noise does become meaningful. If your white point at 400+2EV is the same as at ISO 1600, you lost DR because of the higher RN level at ISO 400 (assuming it is higher...not really the case with the D800/E...definitely the case with the 5D III, D810, A7s, 1DX, etc.) When your saturation point gets low enough, even a fraction of an electron difference in read noise actually becomes quite meaningful as far as dynamic range goes. One electron at very high ISO could mean the difference of a couple stops of DR.



sarangiman said:


> I personally, generally, prefer the flexibility of option (2). But now we're veering off the main point of our discussion, which is that the absence of downstream read noise (high base ISO DR) opens up possibilities otherwise impossible to achieve. And this doesn't come at some high ISO performance cost (compared to Canon). It *didn't* back when the D800 and 5DIII were introduced, and it *doesn't* now.
> 
> And it's a tenuous thread - if not utterly wrong in some cases - to claim that somehow Canon sensors in general are 'superior' to all others with respect to ISO performance. Compared to Exmor or no Exmor.
> 
> *The Nikon files have a bit more magenta in blacks at the highest ISOs, though this could possibly be from ACR's 'Shadows Tint' calibration.



I agree, option 2 is very flexible. I like the idea. I wouldn't call 3-5e- RN the "absence" of read noise...however it is so much lower than 33e- or 38e- read noise that it is quite significant. I still believe that there is value to having <2e- RN at high ISO vs. 3.3e-...the DR formula 20*log(sigSat/RNrms) becomes increasingly sensitive to RNrms the smaller sigSat gets.

The lines of differences in high ISO performance have definitely blurred. The D810 and A7s are performing at a higher level than the D800/E, D600, etc. were at high ISO. Again, I am not sure how the DPR samples demonstrate anything other than differences in color noise tint at high ISO...I'd like to know how the files respond to editing. Not all files respond the same.


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## Gantz (Sep 4, 2014)

*Re: EOS 7D Mark II & Photokina*

Wow and i thought i have too much time today.


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## NancyP (Sep 4, 2014)

*Re: EOS 7D Mark II & Photokina*

Speaking of which, the Sony A7S looks like a killer astro-landscape and extreme low-light camera.

In the "Can you top this" mode concerning sensitivity, check out this news article and links:
http://petapixel.com/2014/09/02/researchers-find-way-to-capture-photos-in-almost-pitch-black-at-only-2-photons-per-pixel/

That should read "Researchers find way to capture photos in almost pitch black at only **** 0.2 **** photons per pixel.


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## Canonicon (Sep 5, 2014)

*Re: EOS 7D Mark II & Photokina*



Canor Rumors said:


> I will release what we have in our possession after the announcement if it turns out we were wrong.



after the announcement.. well that is pretty useless don´t you think?

i guess you meant after the NDA expires... that would be today.


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## neuroanatomist (Sep 5, 2014)

*Re: EOS 7D Mark II & Photokina*



Canonicon said:


> Canor Rumors said:
> 
> 
> > I will release what we have in our possession after the announcement if it turns out we were wrong.
> ...



I suspect CR Guy meant exactly what he said. It would make more sense if you bothered to quote the complete statement:



Canon Rumors said:


> If what we posted *turns out not to be true*, it will be the greatest hoax of specs that I have seen in the 6 years we’ve been around. I will release what we have in our possession after the announcement *if it turns out we were wrong*.



In other words, if the source of his information turns out to be correct, he protects that source. If the information was false, he releases the 'greatest spec hoax in 6 years' so we can all have a laugh. 

Get it now? Or...did you get it before and just selectively quoted his post to be a troll?


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## Xero (Sep 6, 2014)

*Re: EOS 7D Mark II & Photokina*



Don Haines said:


> Canon Rumors said:
> 
> 
> > Lee Jay said:
> ...




I have to agree with this statement. I feel the specs we all have must to be wrong. The suggestion the DPAF will come on the 7d mkII without a touch screen is not logical. How would you pick focus point for the AF without it. Not to mention the fact that all lens and bodies prices are dropping across the board. Something big is coming and we have no idea what it is.... I hope.


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## KacperP (Sep 6, 2014)

*Re: EOS 7D Mark II & Photokina*

That's what you do in industrial espionage - feeding with different types of bs each suspected groups/ppl separately and see what info would leak.


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