# T3 Sensor - question...



## Osiris30 (Feb 10, 2011)

So the T3 (Canon's lowest end DSLR) gets a brand new sensor (the MP count is different than the 450D as is the ISO performance), so I started doing some math.. 

Long story and boring math aside, I'm left with the distinct impression this is a cut down 5D-Mk III sensor. I'm curious to see if anyone else has given this any thought. I just don't see *any* reason for Canon to build a new APS-C sensel w/ gapless microlenses for just one camera (and their cheapest at that).

Anyone?


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## Rocky (Feb 10, 2011)

Osiris30 said:


> So the T3 (Canon's lowest end DSLR) gets a brand new sensor (the MP count is different than the 450D as is the ISO performance), so I started doing some math..
> 
> Long story and boring math aside, I'm left with the distinct impression this is a cut down 5D-Mk III sensor. I'm curious to see if anyone else has given this any thought. I just don't see *any* reason for Canon to build a new APS-C sensel w/ gapless microlenses for just one camera (and their cheapest at that).
> 
> Anyone?



It may be from the Rebel XSi. It is impossible to "cut" a FF sensor to fit an APS_C camera without ALL new tooling (All new Wafer fab process mask set). Then it becomes a new sensor by default. 

It will be nice for Canon to throw in the Gapless micro lens to replace the gapped micro lens on XSi. This will make the 600D to be the best Hiogh ISO Low noise DSLR for the Canon line up, assuming everything else are equal.


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## Admin US West (Feb 10, 2011)

Osiris30 said:


> So the T3 (Canon's lowest end DSLR) gets a brand new sensor (the MP count is different than the 450D as is the ISO performance), so I started doing some math..
> 
> Long story and boring math aside, I'm left with the distinct impression this is a cut down 5D-Mk III sensor. I'm curious to see if anyone else has given this any thought. I just don't see *any* reason for Canon to build a new APS-C sensel w/ gapless microlenses for just one camera (and their cheapest at that).
> 
> Anyone?



This simplest math comes from comparing the resolution to other APS-C sensors from newer models than the XS it replaces. It is likely a derivative of the XSi which is also 4272 X 2848. Its a slightly smallerphysical size, but that could be a result of the closer spaced micro lenses.


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## Grendel (Feb 10, 2011)

Osiris30 said:


> Long story and boring math aside, I'm left with the distinct impression this is a cut down 5D-Mk III sensor.



Not really -- an APS-C sensor w/ the pixel density of the 5DII has about 8.2MP, not the T3's 12MP.


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## Osiris30 (Feb 10, 2011)

Grendel said:


> Osiris30 said:
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> > Long story and boring math aside, I'm left with the distinct impression this is a cut down 5D-Mk III sensor.
> ...



Grendel:

Huh? I said Mk-III not Mk-II.


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## Osiris30 (Feb 10, 2011)

Rocky said:


> Osiris30 said:
> 
> 
> > So the T3 (Canon's lowest end DSLR) gets a brand new sensor (the MP count is different than the 450D as is the ISO performance), so I started doing some math..
> ...



Well the 600D has the same basic sensor as the 60D/550D which is the same basic sensor as the 7D (just cut down readout channels).

And yes I realize what you are saying about cutting an FF sensor down, I didn't mean physically cut down ofcourse, but if you're designing a new 28MP FF sensor, it's actually fairly easy to take that and make a 12MP APS-C at the same time while you're in design (hence cut down). It will be interesting to see what Canon does for FF sensors, probably be the only way to validate the theory I have sadly.


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## match14 (Feb 10, 2011)

Osiris30 said:


> So the T3 (Canon's lowest end DSLR) gets a brand new sensor (the MP count is different than the 450D as is the ISO performance)



The differance in ISO performace could be due to the XSi being digic 3 and the T3 being digic 4.


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## Grendel (Feb 10, 2011)

Osiris30 said:


> Grendel:
> 
> Huh? I said Mk-III not Mk-II.



Heh -- sorry, that late at night it looked like 'II' :-[ I hope Canon will use a lower density in the mkIII (31MP FF, ack). Besides that, I don't think the APS-C/H/FF sensor tech overlaps that much in production -- it's way cheaper to loose a C sensor on a wafer than a FF sensor so you will try to minimize the chance for FF defects. This could include a more robust pixel design, eg. bigger pixels.


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## Osiris30 (Feb 10, 2011)

match14 said:


> Osiris30 said:
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> > So the T3 (Canon's lowest end DSLR) gets a brand new sensor (the MP count is different than the 450D as is the ISO performance)
> ...



I'm sorry you think the difference of *two full* stops (and then some as the ISO 6400 looks better than 1600 ever did on my XSi) is due to a *processor*? Even on my PC there is no way for me to make an XSi image at 1600 look as decent as the samples of this at 6400 OOC. I'm pretty sure Adobe, Neat, etal are pretty good at NR. Certainly there is no hope in hell of me pushing an XSi to anywhere *near* 6400ISO, so no, it's not the Digic.

I think people *really* need to stop thinking the Digic processors are anything more than glorified calculators. They just add, subtract, multiply and shove data around.


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## Osiris30 (Feb 10, 2011)

Grendel said:


> Grendel said:
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It's ok, we've all been there... and I don't mean physically cut down, but if you're designing a new sensel/read out circuitry, there's no reason you can't use it on your APS-C sensor. Conversely, let me ask this; With a 12MP sensor already designed and built for the XSi, why not just use *that* for the T3/1100D. Canon clearly hasn't and has gone to great lengths in their marketing speech to mention this sensor has all the newest goodies in it. 

The business case for doing that design solely your lowest end camera makes no sense to me. I mean they didn't make changes that major for the 600D, 60D or 550D (all they did there was strip/modify the readout circuitry from the 7D sensor). If those, significantly higher margin, cameras didn't warrant a new sensor, why the lowliest of low 1100D?


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## kubelik (Feb 11, 2011)

Osiris30 said:


> So the T3 (Canon's lowest end DSLR) gets a brand new sensor (the MP count is different than the 450D as is the ISO performance), so I started doing some math..



I'm not sure what this thread is predicated on. where/why is the T3's MP count different from the 450D's?

T3 - 4272 x 2848
XSi - 4272 x 2848

yes they may have updated the manufacturing process (I don't know enough about it to know whether changing to gapless microlenses is a big deal), but I also don't know where the assumption that the sensor has changed is coming from. given the fact that the max pixel counts are exactly identical, and that the T3 slots in even cheaper than the XSi, I am of the opinion that it's exactly the same sensor


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## Rocky (Feb 11, 2011)

I agree with Osiris 30 that we should not expect the noise will be substantially better just by switching to a newer processor. I have both the 20D and the 40D. The High ISO (1600) Noise on 40D is worst than the 20D by a very very slight amount even the 40D have a newer processor. In the semiconductor business, sometimes a newer product may be just a cost cutting ( by going to smaller geometry and hence ends up with a smaller chip) move rather than a performance improvement. To be fair, by going to smaller geometry, there may be a gain in the processing speed of the processor.
Therefore, the real improvemnet in noise is by improve the sensor of the XSi ( Gapless microlens, shorten the metal connection, amplifier built into each pixel etc. which is already done on the 7D sensor) and use it on the T3. Canon may end up doing that in order to out perform the Nikon with the same pixel count sensor. That is my wishful thinking.


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## Osiris30 (Feb 11, 2011)

kubelik said:


> Osiris30 said:
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> > So the T3 (Canon's lowest end DSLR) gets a brand new sensor (the MP count is different than the 450D as is the ISO performance), so I started doing some math..
> ...



The radically different high ISO performance for one. Even with PC powered NR in post production the 450D isn't *close* to that good at high-iso.


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## Admin US West (Feb 11, 2011)

Osiris30 said:


> I'm not sure what this thread is predicated on. where/why is the T3's MP count different from the 450D's?
> 
> T3 - 4272 x 2848
> XSi - 4272 x 2848
> ...



The radically different high ISO performance for one. Even with PC powered NR in post production the 450D isn't *close* to that good at high-iso.
[/quote]

Updating from Digic 3 to Digic 4 likely adds at least 3/4 stop. Better noise reduction algorithms probably adds 1/2 stop, Changing to gapless micro lenses and updating the bayer filters, can add 1/2 stop, suddenly you get around 2 stops with the same basic sensor. They can also make a lighter AA filter. All this could make a big difference.

The simplest solution is usually the best one.


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## kubelik (Feb 11, 2011)

Osiris30 said:


> kubelik said:
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osiris, I see the part about IQ being vastly improved. I was more specifically just trying to figure out the part where you noted that "the MP count is different than the 450D" ...

at any rate, to put out a theory as to why canon may have changed the manufacturing to gapless microlenses on a bottom-tier sensor, it could be that, at this point, all future production in going to be done in this fashion anyway. it's actually more costly for them not to go ahead and update their sensor production line for the 12 MP chip than it is for them to just upgrade so that all their machines are running the same process


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## Osiris30 (Feb 12, 2011)

scalesusa said:


> Osiris30 said:
> 
> 
> > I'm not sure what this thread is predicated on. where/why is the T3's MP count different from the 450D's?
> ...



Updating from Digic 3 to Digic 4 likely adds at least 3/4 stop. Better noise reduction algorithms probably adds 1/2 stop, Changing to gapless micro lenses and updating the bayer filters, can add 1/2 stop, suddenly you get around 2 stops with the same basic sensor. They can also make a lighter AA filter. All this could make a big difference.

The simplest solution is usually the best one.
[/quote]

So you're assuming that in camera NR is better than PC powered neat image, etc. done in post on the raw? Sorry but I can't/don't buy it. The 6400 out of the T3 is better than the 1600 PC processed out of the XSi. Gapless ML and bayer yes I'll give you some potential for improvement there (for sure) but that point your entire organics layers have changed which is a huge remask effort, if you're doing that why not update your readout circuitry too... and then all that's left is the core photodiode/well design... at which point why not .. well you get where I'm going 

Not saying you're wrong, but I have a *hard* time putting that much faith in in-camera NR.


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## Osiris30 (Feb 12, 2011)

kubelik said:


> Osiris30 said:
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Well the quoted MP count was different, but it looks like it's the same, so on that I'll have to concede LOL (hey never say I don't admit to being wrong  ).

As for the ML, etc., you may also be right, I just find the performance improvement *so* much better it's really hard for me to think it's even the same base sensor as the XSi.


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## match14 (Feb 12, 2011)

Osiris30 said:


> match14 said:
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Yes I do think that because digic processors are more than calculators they also contain software algorithms for processing raw data e.g. converstion from raw to jpeg in camera. Also amplifiction of the signal from the sensor for different ISO settings is handled by the digic processor, betteramplification algorithims, better noise performace. With each new version of digic comes revised software.

Obviously the change in processor alone is not the only thing to improve ISO performance but it surely plays a part.


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## unruled (Feb 12, 2011)

match14 said:


> Osiris30 said:
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JPG processing is one thing, and newer digic procs may have different processing which creates cleaner output.... but obviously if you shoot raw, you bypass anything that DIGIC may do to it. For RAW, whether you have a digic 2 or 4... will do absolutely nothing for you (other than faster processing speeds, etc).


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## S P (Feb 12, 2011)

Quite interested in the performance of this new sensor also. Just am not a fan of the massively squeezed 18MP sensor on all of the other cams. Waiting for comparative data to show up on DxOMark.com


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## Osiris30 (Feb 13, 2011)

match14 said:


> Osiris30 said:
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Digic's don't contain "software algorithms". That is in the firmware. Ignoring for a minute that software doesn't live in hardware. Amplification is not handled by the Digic either, it's handled by the onboard pixel level signal amps. Digic are ARM core based (I believe) processors with SIMD functionality. Digic's are just basic logic cores to control the machine coupled with some simd/matrix multiplication support circuitry. I would *strongly* suggest you research what ASICs are, and the functionality they general contain before you make any more statements about what the Digic does or does not do.


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## Osiris30 (Feb 13, 2011)

unruled said:


> match14 said:
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At best the Digic will have a hardware assist for debayer (not even the entire routine, just key choice 'expensive' parts implemented in silicion and maybe some of the quanitization that is needed for jpeg compression. The basic jpeg control loop is still run by firmware using general purpose instructions. It has to be, or the Digic would be the size of the camera.


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## Woody (Feb 13, 2011)

S P said:


> Quite interested in the performance of this new sensor also. Just am not a fan of the massively squeezed 18MP sensor on all of the other cams. Waiting for comparative data to show up on DxOMark.com



Let's see now... the 16 MP D7000 outdoes the 12 MP D300s/D90/D5000 by a fair margin. So, what say you to that?

Also, we'll soon see 24 MP APS-C sensors on the upcoming Sony A77 and Nikon D400. When that happens, I challenge you to go on the web to blast those cameras for their SUPER MASSIVELY SQUEEZED sensors. Really. So far, no one is taking up that challenge... especially those Nikon/Sony fanboys.


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## Admin US West (Feb 13, 2011)

Osiris30 said:


> Digic's don't contain "software algorithms". That is in the firmware. Ignoring for a minute that software doesn't live in hardware. Amplification is not handled by the Digic either, it's handled by the onboard pixel level signal amps. Digic are ARM core based (I believe) processors with SIMD functionality. Digic's are just basic logic cores to control the machine coupled with some simd/matrix multiplication support circuitry. I would *strongly* suggest you research what ASICs are, and the functionality they general contain before you make any more statements about what the Digic does or does not do.



Although Digic 4 is a processor system, and firmware is in a separate memory chip, the net result is more speed and the ability to process more complex algorithms, and thus improve images over Digic III.

Its just a matter of nitpicking the wording that is in Canon's white paper quoted below, a person does not need to be a engineer and research ASIC's and firmware to know that cameras with Digic 4 produce images with less noise.

From Canon.

DIGIC 4
The DIGIC 4 processor first appeared in the EOS 50D camera launched in Autumn 2008 and is also featured in the EOS 5D Mark II. Compared to DIGIC III and the previous incarnations of DIGIC, the DIGIC 4 offers several advancements. 

A more powerful processor can carry out more processing in the same time and therefore perform more advanced processing functions. The DIGIC 4 is actually about 1.3 times faster at signal processing when compared to a DIGIC III and this has several effects. It produces lower image noise for smoother images at every ISO setting and it also allows the extreme expansion (ISO) settings of H1 (12,800) and H2 (25,600) on the EOS 5D Mark II. 

The extra processing speed also helps if high ISO noise reduction is enabled. The cameras can retain their burst rate and shooting speed in all but the highest level of noise processing. 

Enlarge imageThe DIGIC 4 processor first appeared in the EOS 50D. 

Much of the DIGIC 4 processing is similar to the DIGIC III but it has also added some new features such as Peripheral Illumination Correction to counter the possibility of corner shading, Face Detection AF in Live View mode, and UDMA class 6 card compatibility. 

In the EOS 5D Mark II it has added the ability to shoot full HD 1080p movie with sound because the processor can deal with the data fast enough to process it out to the memory card without bottle necks. 

Overall, DIGIC 4 means that the cameras capture images with visibly better image quality. 

The EOS 7D and EOS-1D Mark IV both feature Dual DIGIC 4 processors. The benefits are the same as having a single processor in the EOS 5D Mark II, but with two processors the processing speed is faster â€“ this allows these cameras to deal with high resolution images at 8fps and 10fps respectively. 

The extra processing power has also allowed 50 and 60fps HD movie recording at 720p as well as higher ISO capabilities, with the EOS-1D Mark IV featuring ISO expansion up to ISO 102,400.


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## S P (Feb 13, 2011)

Woody said:


> S P said:
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> > Quite interested in the performance of this new sensor also. Just am not a fan of the massively squeezed 18MP sensor on all of the other cams. Waiting for comparative data to show up on DxOMark.com
> ...



I'd say you're misinformed.

People who actually own the D7000 on the Nikon forums say it edges the D300s and D90 cameras very slightly, but no it isn't by a fair margin. Where it does best is in low-ISO dynamic range, which is precisely what the DxOMark data illustrates. Besting those cameras by a "fair margin" would be the full frame D700, and no the D7000 still isn't touching that camera.



Woody said:


> Also, we'll soon see 24 MP APS-C sensors on the upcoming Sony A77 and Nikon D400. When that happens, I challenge you to go on the web to blast those cameras for their SUPER MASSIVELY SQUEEZED sensors. Really. So far, no one is taking up that challenge... especially those Nikon/Sony fanboys.



Actually I don't have to do a thing, because sites like DxOMark.com already are.  Go fire up a comparison between the Canon 60D, 50D, and 40D, click on the SNR tab and PRINT size comparison and you'll see that they all resolve practically the SAME amount of detail. 

link

The 18MP sensor doesn't resolve noticeably more detail than even the 10MP. The resolution limits of an APS-C sensor with today's lenses has already been reached at about the 12MP level, so what's a 24MP APS-C sensor gonna do? Merely continue splitting the same limited amount of detail into more and more pixels. What's the point? Why is it that when you jump up to a full-frame 12MP sensor like in the D700, that the 12MP sensor will resolve MORE detail than the 18MP APS-C? A 21/24MP full-frame sensor will resolve a crap ton more detail than a 24MP APS-C sensor. That's the advantage of bigger photosites and a larger format. It's the laws of physics with diffraction limits that you're working against, so there's no magical pixie dust that you can sprinkle on the camera to miraculously get it to resolve every single one of those pixels. The biggest reason for a 24MP APS-C sensor is for marketing. I doubt Nikon will use a 24MP APS-C sensor from Sony in the D400. I'm guessing they'll use a tweaked version of the 16MP sensor that's already in the D7000.

Personally I'm a much bigger fan of Nikon's more constrained megapixel approach to sensor design, in limiting the number of megapixels but cranking up the quality of each of those pixels with better dynamic range and color accuracy and lower noise. It's why their full-frame sensors with only 12MP are such hot performers. 100% crops from these cameras look spectacular, but every single 100% crop I've seen from the Canon 18MP APS-C sensors have looked soft and fuzzy to me. If I really wanted 18MP I'd just shoot my 5D Mark II. 8) There's little point to such high-res in APS-C if you ask me.

That said, the reason I've held off on buying a secondary body is because I haven't been impressed with Canon's APS-C sensors. This new sensor in the T3/600D has a lot of potential because its photosites will be bigger, and it'll have the much more modern processing engine. Somehow I doubt Canon would allow the cheaper camera body to outperform the more expensive ones though, so I'm not getting my hopes up. :


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## Rocky (Feb 13, 2011)

S P said:


> That said, the reason I've held off on buying a secondary body is because I haven't been impressed with Canon's APS-C sensors. This new sensor in the T3/600D has a lot of potential because its photosites will be bigger, and it'll have the much more modern processing engine. Somehow I doubt Canon would allow the cheaper camera body to outperform the more expensive ones though, so I'm not getting my hopes up. :


I am totally agree with you and the rest of the discussion on your post. Just hope Canon is smart enough to turn the T3 into a High ISO performer and let the people that want 18MP to have the 7D, 60D or the T3i. I am going to throw another coal into the fire. Last night I was looking at the noise performance (only) of 40D, 7D and 60D with DXOmark. At ISO1600 and 3200, 40D is the best performer by a slight margin. This says a lot about the noise and pixel size.


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## S P (Feb 13, 2011)

Yeah.

All Canon has done with their photosite and sensor tech advancements and Digic processing over the past couple of years is use all of that to maintain about the same quality while cranking the megapixel count all the way up. They've been moving forward on megapixel count, but standing still as far as overall IQ (and actually going backwards as far as per-pixel IQ). Nikon has taken the opposite approach of holding the megapixel count relatively steady, but using all of the tech advancements to actually improve image quality. Compare the Nikon D90 to the Canon 60D and both resolve about the same detail (SNR, the extra 6MP in the 60D buys you what again??), but the D90 is significantly better in terms of everything else - dynamic range, tonal range, and color sensitivity. The D90 actually performs about on par with the Canon 5D classic, which is pretty impressive. I had a D90 with Nikon and it indeed delivered very impressive image quality. I don't want to feel like I'm going backwards. No urgent need for a secondary/backup body so I've just been holding off.


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## WarStreet (Feb 13, 2011)

Rocky said:


> Last night I was looking at the noise performance (only) of 40D, 7D and 60D with DXOmark. At ISO1600 and 3200, 40D is the best performer by a slight margin. This says a lot about the noise and pixel size.



From DXO I can see that the SNR of the 60D and 70D is better than the 40D in the high ISO range. May I ask how you are comparing these cameras ? Are you checking the print results ?


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## S P (Feb 13, 2011)

Yes, you do need to be clicking on the 'Print' rather than the 'Screen' tab with DxOMark data, which levels the playing field by normalizing both images to the same equivalent print sizes. With the 'Screen' tab it's effectively 100% on screen viewing that you're comparing, but comparing the 40D images at a smaller (less demanding) print size and the 7D/18MP ones at a larger (more demanding) print size, which gives an unfair advantage to the lower meg sensor.

The 18MP sensors do have a very slight advantage at high ISO due to probably newer and more advanced sensor tech (hardware) and also newer processing engines, but it's surprisingly even overall. The different would be much more significant and noticeable if Canon had applied all of the newer tech while holding MP's steady as Nikon has been doing.


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## Woody (Feb 14, 2011)

S P said:


> Actually I don't have to do a thing, because sites like DxOMark.com already are.  Go fire up a comparison between the Canon 60D, 50D, and 40D, click on the SNR tab and PRINT size comparison and you'll see that they all resolve practically the SAME amount of detail.



WRONG. 

The PRINT tab in DXOMark shows images from the various cameras DOWN rez to 8 MP. Take a good look at this site which performed controlled testing on various APS-C cameras and compared their RAW output by UP rez them to 40 MP:
http://pixinfo.com/cikkek/dslr_evolution.3
The 18 MP 7D destroys all other APS-C cameras in that comparison (from Canon 10D to 50D, from Nikon D100 to D300) for image quality at all ISO levels.


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## Woody (Feb 14, 2011)

S P said:


> The different would be much more significant and noticeable if Canon had applied all of the newer tech while holding MP's steady as Nikon has been doing.



Errr.. you are out of touch with the current state of affairs. Clearly, you have NOT noticed the Nikon D3100 is 14 MP and the D7000 is 16 MP. On the other hand, the 600D has the same pixel count as the 550D, 60D and 7D. So, Canon has been holding the pixel count steady while Nikon is increasing theirs... and soon Nikon/Sony will be going for 24 MP.

Addendum:
In case you think Nikon improved on the Sony sensor technology in their D90 and D5000 as compared to the D300, that is wrong also. There is definitive proof that all Nikon did was to introduce destructive (albeit sneaky) in-camera RAW NR. I have the link at home and can post it later. This is one of those things NOT captured by the limited DXOMark tests.

Most interestingly, the D300s (released after the D90 and D5000) does not have the same in-camera RAW NR. The postulate is the processor at that time cannot cope with the relatively high fps of the D300s (as compared to D90/D5000). It appears that sneaky destructive in-camera RAW NR is practised by everyone these days EXCEPT Canon who wants to continue their support for the small astro-photography crowd. Sony did the same with their RAW files at one point but seemed to have stopped the practice after the barrage of complaints.

Addendum 2:
Proof of in-camera RAW NR on D90:
http://forums.dpreview.com/forums/read.asp?forum=1032&message=32401883
Not sure if the pics will load 'cos the poster, Gabor, has passed away.


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## WarStreet (Feb 14, 2011)

S P said:


> Actually I don't have to do a thing, because sites like DxOMark.com already are.  Go fire up a comparison between the Canon 60D, 50D, and 40D, click on the SNR tab and PRINT size comparison and you'll see that they all resolve practically the SAME amount of detail.
> 
> link



Using DXO comparing 40D, 50D and 7D (60D not available for resolution measures) it shows that there is about 3 to 5 lp/mm difference between these cameras even with a low performance lens such as 28-135 wide open. The better the lens, the bigger the gap. One has to convert these numbers into the actual print size. 

For example comparing the 7D vs 50D with the 28-135mm @28mm F5.6, the difference is about 5 lp/mm at the center and compared to the center measurement of the 50D which is about 45 lp/mm it means you have more than 10% larger print or cropping ability. 



S P said:


> The 18MP sensor doesn't resolve noticeably more detail than even the 10MP. The resolution limits of an APS-C sensor with today's lenses has already been reached at about the 12MP level, so what's a 24MP APS-C sensor gonna do?




As mentioned above DXO shows that 7D has better resolving power than a 50D. Sensor resolution and optics, do not limit each other but compliment each other. That's why I used a low performance lens in the comparison. Eventually there is a limit, where more resolution won't improve lp/mm, but it seems we are far from that. 



S P said:


> Why is it that when you jump up to a full-frame 12MP sensor like in the D700, that the 12MP sensor will resolve MORE detail than the 18MP APS-C? A 21/24MP full-frame sensor will resolve a crap ton more detail than a 24MP APS-C sensor.



An FF camera has the advantage of using all the lens glass instead a fraction of it on an APS-C, and optics compliment the lp/mm. Using DXO, it shows that 12mp FF can compete with a 18MP APS-C. When I compared the 7D with the D700, with similar category lenses, their lp/mm is not far from each other, with usually a slight edge for the 7D. On the other hand a 21mp FF will have a significant lp/mm over a 12mp FF.




S P said:


> It's why their full-frame sensors with only 12MP are such hot performers. 100% crops from these cameras look spectacular, but every single 100% crop I've seen from the Canon 18MP APS-C sensors have looked soft and fuzzy to me.



If both are compared at 100% crop, the APS-C 18mp for sure will be softer. You need to compare with the same print size. the 18mp sensor will represent a bigger print than a 12mp sensor, when compared at 100%. If you compare with the same print size as DXO do, you should see similar sharpness, as showed from DXO comparing 12mp FF vs 18mp APS-C. Also, the noise gap decreases too, although FF or lower res APS-C cameras, will always win in this department !


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## Rocky (Feb 14, 2011)

Rocky said:


> Last night I was looking at the noise performance (only) of 40D, 7D and 60D with DXOmark. At ISO1600 and 3200, 40D is the best performer by a slight margin. This says a lot about the noise and pixel size.



Sorry, I was looking at the raw data(screen mode). The print mode does give the 18Mp sensors(7D and 60D)an edge on the high ISO noise. Thanks for all the advices of using DXOMark.


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## S P (Feb 14, 2011)

Woody said:


> S P said:
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> 
> > Actually I don't have to do a thing, because sites like DxOMark.com already are.  Go fire up a comparison between the Canon 60D, 50D, and 40D, click on the SNR tab and PRINT size comparison and you'll see that they all resolve practically the SAME amount of detail.
> ...


Not from what I've seen. 

Just because DxO downsizes to to a standard print size doesn't invalidate their methodology. What you're suggesting is that the downsizing doesn't show the difference of higher MP count sensors, when in fact it still does. Compare a D90 to a 60D to a Nikon D3x. The D3x scores a 43.9dB SNR at base ISO, vs 39dB for the 60D and 38.4dB for the D90. The extra 6MP from the Canon's sensor buys you a whopping 0.6dB over the D90. Wow. The reason the 60D isn't closer to the D3x and its resolution doesn't scale linearly is because it's approaching the physical limits of resolution of that sensor size whereas the D3x isn't quite at the same limits.

As for the comparison you linked, I have no idea what to make of that and have never seen such blurry D200 and D300 images. It almost looked like they were slightly out of focus or didn't have the same sharpening applied. And if you look at the other image samples you can even see lighting change from shot to shot, so not exactly the most scientific setup. I even see camera company advertising directly on the website, which gives me further reason to not trust it. I've seen other comparison between the Canon 18MP APS-C and the Nikon 12MP APS-C and some full-frame sensors from trusted and camera manufacturer independent sources that show pretty much what DxO's data illustrates. Basically no difference between 12 and 18 on an APS-C, or if the 18MP does show a little bit more detail it's nothing to write home about when you compare it to a full-frame sensor. It makes it plain as day obvious that if ultimate resolving power is what you want full-frame is the solution, not more and more pixels crammed into APS-C. Hence my preference for more megapixel constrained sensors esp on APS-C that focus on other image quality attributes such as dynamic range and color accuracy, etc.


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## Rocky (Feb 14, 2011)

After reading more on different photo sites and forums here. I have the following thought:
1. There is s "slight" improvement between the 18MP and 10MP. But is the improvement worth the files being twice as big. 
2. The improvement in the 18MP over 10Mp is it due to the sensor itself or due the processor and 14 Bit vs. 12 bit color depth? Also the improvement shows after the 18MP is down sized to be 10MP. 
3. Everything that I have read says the existing lenses (even the L lenses) cannot resolve more than 14 MP on APS_C. How true is it???
4. Based on the DXOMark data, the lens/sensor combination can only resolve about 50 lpmm. That translates to be about 3.4 MP. What is wrong with this picture??
5. If #4 is true, then the debate between 18MP and 10 Mp is almost a waste of time in terms of resolution.
6. One of the site compares different sensor by scaling them all up to 40MP. This is not a fair test. The 18MP will always MUCH better than the 10 MP in terms of sharpness.
I am not trying to take side. Just hope someone in this forum can shine some light on the above points.


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## Admin US West (Feb 15, 2011)

Resolution of a lens / sensor combination is going to always be much lower than a person would expect. The system resolution is equal to the product of the MTF of the individual components.

If your lens has a mtf of .7 and your camera 0.7, the result is 0.49, much lower than either one. The way to increase the system resolution is to increase the mtf of the components.

Increasing the megapixel count in a camera increases its mtf. noise reduction, noise, and AA filters as well as other factors including the firmware also affect the mtf of the body.

This was exactly the same issue with film, each layer of the emulsion has a mtf and the total mtf of the film is the product of the three, then multiply that by lens mtf, and very quickly, the system mtf drops off sharply.

A printer or a computer monitor screen drops it a whole lot more. Its a struggle to keep the resolution up.


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## S P (Feb 15, 2011)

Woody said:


> S P said:
> 
> 
> > The different would be much more significant and noticeable if Canon had applied all of the newer tech while holding MP's steady as Nikon has been doing.
> ...



Nikon's pro bodies both APS-C and full-frame are all still at 12MP, with the exception of the D3x which few actually buy. So I really don't think it's accurate to say that Nikon is cranking up their MP count while Canon is "holding steady". Yes the D3100 and 7000 have recently gone up to 14 and 16, but that's still less than what Canon has been at for awhile - 18MP. A prominent Nikon analyst/shooter thinks the only reason they went up that much in the first place was merely to "keep up appearances" with Canon in the whole MP race, and would have been more than happy to stay lower except for that.



Woody said:


> Addendum:
> In case you think Nikon improved on the Sony sensor technology in their D90 and D5000 as compared to the D300, that is wrong also. There is definitive proof that all Nikon did was to introduce destructive (albeit sneaky) in-camera RAW NR. I have the link at home and can post it later. This is one of those things NOT captured by the limited DXOMark tests.



I've owned a D90 and shot it side by side with a D300 and have seen plenty of comparisons elsewhere, and the D90 is definitely better. Resolving power is roughly the same, but the D90 has much improved dynamic range which is what DxOMark shows, and what I've seen with my own two eyeballs looking at images that I've taken. The D90/5000 sensor IS IMPROVED over the D300 in those areas.


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## match14 (Feb 26, 2011)

scalesusa said:


> Osiris30 said:
> 
> 
> > Digic's don't contain "software algorithms". That is in the firmware. Ignoring for a minute that software doesn't live in hardware. Amplification is not handled by the Digic either, it's handled by the onboard pixel level signal amps. Digic are ARM core based (I believe) processors with SIMD functionality. Digic's are just basic logic cores to control the machine coupled with some simd/matrix multiplication support circuitry. I would *strongly* suggest you research what ASICs are, and the functionality they general contain before you make any more statements about what the Digic does or does not do.
> ...



Yes there is more to Digic 4 processing than just the processor. Thats why it is called Digic 4 processing not processor, as it is processing the data so I still stand by my original claim that Digic 4 vs Digic 3 is one of the main differences for the ISO performace of the T3 and XSi.


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## Admin US West (Feb 26, 2011)

match14 said:


> Yes there is more to Digic 4 processing than just the processor. Thats why it is called Digic 4 processing not processor, as it is processing the data so I still stand by my original claim that Digic 4 vs Digic 3 is one of the main differences for the ISO performace of the T3 and XSi.



We do not yet know if there is any difference in sensor performance, just that jpeg images look better. Once there are production cameras and raw files can be viewed and tested, then we can see if the sensor is better. 

A better jpeg image due to a more powerful processor is one thing, but if RAW performance is better, than the sensor or AA filter, etc is likely changed.

You cannot tell with the data existing today, only make a guess.


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## WarStreet (Feb 26, 2011)

scalesusa said:


> A more powerful processor can carry out more processing in the same time and therefore perform more advanced processing functions. The DIGIC 4 is actually about 1.3 times faster at signal processing when compared to a DIGIC III and this has several effects. It produces lower image noise for smoother images at every ISO setting and it also allows the extreme expansion (ISO) settings of H1 (12,800) and H2 (25,600) on the EOS 5D Mark II.



Scalesusa, could you clarify if the noise improvement you are referring by an improved processor, is acting before the raw file has been created during the analog to digital conversion, or after the raw file has been created ? 

I am assuming that this improvement is done before the raw file has been created otherwise any pc will get a better image. Also, if this is so, There must be a limit on how much processing power the perfect algorithm needs, so once reached, a better processor won't give any improved noise, and only a better sensor can improve it. I am curious how far we are from such a limit. Is this correct or not ?


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## Admin US West (Feb 26, 2011)

Scalesusa, could you clarify if the noise improvement you are referring by an improved processor, is acting before the raw file has been created during the analog to digital conversion, or after the raw file has been created ? 

I am assuming that this improvement is done before the raw file has been created otherwise any pc will get a better image. Also, if this is so, There must be a limit on how much processing power the perfect algorithm needs, so once reached, a better processor won't give any improved noise, and only a better sensor can improve it. I am curious how far we are from such a limit. Is this correct or not ?
[/quote]

This was a quote from a Canon white paper explaining the improvements in the Digic IV over Digic III.

Raw images do not have in camera processing, the data from the sensor is processed in your pc. This is a simplification, but basically true.

The processing part is where the camera produces jpeg images from the Raw data and saves a jpeg image to the flash card , or perhaps in addition to RAW data. That in camera processor is nowhere near as powerful as a pc, and, since it has to process the images on the fly, it is limited as to what things it can do.

By processing RAW images in your PC using some of the high powered software available, you can apply selective noise reduction to parts of the image, have a huge range of control over colors, more comtrol over brightness, contrast, and a host of controls to opptimize your image. you can work on one image at a time, or set the process to run on all images.

The software keeps getting more powerful and continues to keep even high powered pc's loaded down. I do not expect to ever see the processor in a Camera keep up with what a PC can do, but, as in camera processing improves, so do jpeg in-camera images.


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## WarStreet (Feb 26, 2011)

scalesusa said:


> Raw images do not have in camera processing, the data from the sensor is processed in your pc. This is a simplification, but basically true.



I thought Canon white paper was referring to some type of processing at the analog to digital conversion of the bayer sensor. Since they were referring to the standard processing of the raw file, we can say that the camera processor has nothing to do with the noise performance of the raw file. I knew this, but started to get in doubt after reading several posts of improved noise with better processors. They were just referring for the processed raw and not for some processing before the raw creation. Thanks for the clarification.


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## Admin US West (Feb 26, 2011)

WarStreet said:


> scalesusa said:
> 
> 
> > Raw images do not have in camera processing, the data from the sensor is processed in your pc. This is a simplification, but basically true.
> ...



Like i said, that is the simple story. Depending on Camera manufacturer, you can change settings to add in noise reduction. Canon, for now, lets you turn it off, other manufacturers may not.

It becomes very complex, so just look at it simply, you can spend a lot of time and merely discover that no one except Canon knows exactly what modifications are applied to a RAW image in camera, but it is thought to be very minimal.


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