# So sayeth DXO: "The a7R II poops on the 5DS"



## ahsanford (Aug 27, 2015)

Well, that just happened...

http://www.dxomark.com/Cameras/Compare/Side-by-side/Sony-A7R-II-versus-Canon-EOS-5DS-versus-Nikon-D810___1035_1008_963

- A


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## ahsanford (Aug 27, 2015)

You've got to love DXO's Fox News-ness about their shtick. Amazing.

Number of Canon lenses retested on the 5DS? *Zero.* They wouldn't want the world's 1,064th best lens -- _the Canon 70-200 f/2.8L IS II_ -- suddenly becoming the world's 20th best lens all of sudden. 

(Because their lens rating system is dominated by how many pixels are looking at it. You know. _That_.)

They could not re-test a *single* lens before they got their a7R II review completed. One might expect they'd now withhold all Canon lens retesting until they have the Sony lenses retested as well. Classic DXO.

- A


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## LOALTD (Aug 27, 2015)

*Sony A7R II scores 98, new king of DxO Mark (by a nose)*

How has this not been posted yet? Forgive and delete if it has:


http://www.dxomark.com/Cameras/Sony/A7R-II


Nikon D810 has slightly more DR, not as good at high ISO.


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## dolina (Aug 27, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*

Bodies changes in 1/2/3 years.

Lenses changes in 1/2/3 decades.

Mirrorless is the future.


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## Mt Spokane Photography (Aug 27, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*

DXO does not rate a camera, just the sensor. A camera can have all kinds of issues and problems, and might be totally unsuitable for most photographers, but they will rate it high if they like the sensor.

As long as a person understands that and evaluates the rest of the camera, you can build the total picture.


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## chromophore (Aug 27, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*

"King of DxOMark" = "Best random number DxO decided to keep."

Because that's what those scores mean. It is purely a reflection of DxO's personal impressions of how much they like a particular sensor and a particular brand, nothing more.


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## Phenix205 (Aug 27, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*

Whether DXO's rating is biased or not, the a7r II is the best in its class from many users' real world shooting experience. Cry next camera will be a Sony full frame mirrorless.


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## LOALTD (Aug 28, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*



Mt Spokane Photography said:


> DXO does not rate a camera, just the sensor. A camera can have all kinds of issues and problems, and might be totally unsuitable for most photographers, but they will rate it high if they like the sensor.
> 
> As long as a person understands that and evaluates the rest of the camera, you can build the total picture.




Definitely! This score doesn't even take into account the in-body image stabilization, class-leading 4k video, or solid AF with Canon glass.


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## 3kramd5 (Aug 28, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*



LOALTD said:


> Mt Spokane Photography said:
> 
> 
> > DXO does not rate a camera, just the sensor. A camera can have all kinds of issues and problems, and might be totally unsuitable for most photographers, but they will rate it high if they like the sensor.
> ...



If I ranked it based on AF with canon glass it would negatively affect the score. That's not fair, though. AF should only be based on native glass, which is quite good (and ignored by DXO).




Mt Spokane Photography said:


> DXO does not rate a camera, just the sensor. A camera can have all kinds of issues and problems, and might be totally unsuitable for most photographers, but they will rate it high if they like the sensor.
> 
> As long as a person understands that and evaluates the rest of the camera, you can build the total picture.



When they redesigned the site they started calling them "camera" scores, but yes they are still based on sensor measurement and don't represent cameras in any reasonable way.


DXO is neat, but I don't really care. It could have scored 2 or 200, I'd still keep mine.


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## bmwzimmer (Aug 28, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*

Looking at the signal to noise ratio/dynamic range/color tonality/etc... Throughout the ISO range in both screen and print, it really is a significant leap ahead of the d810 and 5dsr. 
Props to Sony for a hell of a sensor design. Unfortunately for Sony, dxo only gives it a point more than the d810 when it should be heaps higher because it does so much better at higher ISO's


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## ahsanford (Aug 28, 2015)

The formal story just dropped:
http://petapixel.com/2015/08/28/dxomark-the-sony-a7r-ii-has-the-best-sensor-weve-ever-seen/

- A


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## IglooEater (Aug 28, 2015)

ahsanford said:


> You've got to love DXO's Fox News-ness about their shtick. Amazing.
> 
> Number of Canon lenses retested on the 5DS? *Zero.* They wouldn't want the world's 1,064th best lens -- _the Canon 70-200 f/2.8L IS II_ -- suddenly becoming the world's 20th best lens all of sudden.
> 
> ...



Actually I doubt will see many if any 5ds lens ratings before the nikon d850? D900? Whatever nikon inherits the new Sony sensor gets rated.


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## 3kramd5 (Aug 30, 2015)

ahsanford said:


> Well, that just happened...



I don't get it.

[quote author=http://www.dxomark.com/Reviews/Sony-A7R-II-sensor-review-New-high-water-mark-in-sensor-dynamics/The-new-leader-in-the-DxOMark-database]With an overall DxOMark score of 98 points, the Sony A7R II achieves the highest marks for performance of any sensor that we’ve seen to date[/quote]

[quote author=http://petapixel.com/2015/08/28/dxomark-the-sony-a7r-ii-has-the-best-sensor-weve-ever-seen/]It looks like the hype surrounding the new Sony a7R II is justified… at least when it comes to sensor quality. DxOMark tested backside-illuminated full-frame sensor in the camera — a world’s first — and the sensor received the highest overall quality score ever awarded by the testing lab.[/quote]

Are we supposed to pretend the Red Epic Dragon didn't score 101? Are they disavowing it because it was a prototype?


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## privatebydesign (Aug 30, 2015)

3kramd5 said:


> ahsanford said:
> 
> 
> > Well, that just happened...
> ...



[quote author=http://petapixel.com/2015/08/28/dxomark-the-sony-a7r-ii-has-the-best-sensor-weve-ever-seen/]It looks like the hype surrounding the new Sony a7R II is justified… at least when it comes to sensor quality. DxOMark tested backside-illuminated full-frame sensor in the camera — a world’s first — and the sensor received the highest overall quality score ever awarded by the testing lab.[/quote]

Are we supposed to pretend the Red Epic Dragon didn't score 101? Are they disavowing it because it was a prototype?
[/quote]

Just wait until the DXO Two comes out, or maybe they will call it the DXO One MkII, anyway in its SuperDuper RAW mode it will beat the pants off the Sony just like the One does to the 5D MkIII now :


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## Mitch.Conner (Aug 30, 2015)

While I don't really know what to think of dxo, and I don't want to get into a debate about them, is anyone really questioning that the a7rii has an amazing sensor?


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## privatebydesign (Aug 30, 2015)

Mitch.Conner said:


> While I don't really know what to think of dxo, and I don't want to get into a debate about them, is anyone really questioning that the a7rii has an amazing sensor?



No, I doubt it. But lets keep it in perspective, even if you embrace the DXO scores it is 1 point 'better' than the Nikon D810, DXO says 5 points equates to 1/3 stop of sensitivity, so this _new amazing sensor_ is 1/15 stop better than we already have.

We are not game changing here, there is a very modest improvement over the MkI, 3 DXO points, or 1/5 stop, and a 16% increase in MP, or 12% more linear resolution.


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## 3kramd5 (Aug 30, 2015)

privatebydesign said:


> 3kramd5 said:
> 
> 
> > ahsanford said:
> ...



Are we supposed to pretend the Red Epic Dragon didn't score 101? Are they disavowing it because it was a prototype?
[/quote]

Just wait until the DXO Two comes out, or maybe they will call it the DXO One MkII, anyway in its SuperDuper RAW mode it will beat the pants off the Sony just like the One does to the 5D MkIII now  :
[/quote]

Oh god please let them call it the DXO One Two. Each new model can add a sequential numeral spelled out, and an additional blended exposure. Then in a few generations they can pull a Microsoft and jump to DXO One Ten.


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## Larsskv (Aug 30, 2015)

ahsanford said:


> You've got to love DXO's Fox News-ness about their shtick. Amazing.
> 
> Number of Canon lenses retested on the 5DS? *Zero.* They wouldn't want the world's 1,064th best lens -- _the Canon 70-200 f/2.8L IS II_ -- suddenly becoming the world's 20th best lens all of sudden.
> 
> ...



+ 1


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## Bennymiata (Aug 30, 2015)

I don't doubt that the new Sony sensor is probably one of the best available now, but it's like having a great engine in a car with a jerky gearbox and rough suspension.
It looks good on paper but you don't want to drive it much.


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## 3kramd5 (Aug 30, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*



dilbert said:


> bmwzimmer said:
> 
> 
> > Looking at the signal to noise ratio/dynamic range/color tonality/etc... Throughout the ISO range in both screen and print, it really is a significant leap ahead of the d810 and 5dsr.
> ...



Probably not much. See D800 compared with A7R.


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## Mitch.Conner (Aug 31, 2015)

privatebydesign said:


> Mitch.Conner said:
> 
> 
> > While I don't really know what to think of dxo, and I don't want to get into a debate about them, is anyone really questioning that the a7rii has an amazing sensor?
> ...



I didn't mean that it was amazingly better than its predecessor, just that it is an impressive piece of tech. Amazing to me.


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## Mitch.Conner (Aug 31, 2015)

Bennymiata said:


> I don't doubt that the new Sony sensor is probably one of the best available now, but it's like having a great engine in a car with a jerky gearbox and rough suspension.
> It looks good on paper but you don't want to drive it much.



But hopefully other companies that know how to build cars well will buy that engine to put in their cars.

Or, alternatively, maybe other car companies will try to push their engine technology to try to keep up with the state of the art.

Did I take the analogy too far?


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## Sporgon (Aug 31, 2015)

Mitch.Conner said:


> Bennymiata said:
> 
> 
> > I don't doubt that the new Sony sensor is probably one of the best available now, but it's like having a great engine in a car with a jerky gearbox and rough suspension.
> ...



They are: Pentax in November. 

Seriously though, if anyone thinks this BLS Exmor is significantly better than the 50 MP Canon in practice they'd better enjoy digging deep into those niches. It's a little like a Canon user repeatedly demonstrating that their 50 MP sensor has slightly more detail.......


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## 3kramd5 (Aug 31, 2015)

Sporgon said:


> Mitch.Conner said:
> 
> 
> > Bennymiata said:
> ...



Is that more than rumored at this point? I read something about Pentax using the sensor in a $2000 camera, which would be impressive indeed. The sensor is likely the most expensive part of the A7R2. If a third party can offer than sensor packaged in a camera for $1,200 less, wow. Granted, maybe Sony's camera division ate ALL the development costs and Pentax is getting it at the production-amortized value, but that would be silly business.

Shrug.


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## Sony (Aug 31, 2015)

Well, it's a good news. But the best news: tomorrow I will get a 5DS R, not a7R II, from B&H. Lol.


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## privatebydesign (Aug 31, 2015)

dilbert said:


> ahsanford said:
> 
> 
> > ...
> ...



That weak reply hardly mitigates the accurate comments about easily evidenced DXO anti Canon bias.

We all refer to DXO on occasions and it is interesting to see the corporate bias so clearly as is this case.

The test results are not just a "free side show" they are a key element to the DXO marketing strategy by keeping their company profile in the news and in peoples faces. As far as marketing budgets go it costs them next to nothing, presenting their good measurements that they need to take for their products (the expensive bit) and presenting them in some bullshit black box proprietary format biased against companies they haven't worked with (the cheap bit, both financially and ethically).


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## ahsanford (Aug 31, 2015)

dilbert said:


> That aside, I expect that the lens test results will get updated on the web after DxO have test results integrated into an update for DxO Optics. DxO Optics is their product that people pay money for, the rankings and scoring is just a side show the Internet gets to consume for free.



Someone else on this forum who uses DxO optics stated that the 5DS / 5DS R profiles have already been updated -- not knowing the program, does that mean lens testing on those rigs have been completed? (I don't use that program so I don't know.)

I generally roll my eyes at DXO more than hate them, but their _lens rankings_ (not the score) need to be thrown out. See attached -- that's misleading _at best_. Just report how lenses perform and be done with it. An overall lens ranking implies there is a standardized means to look at lenses across all mounts -- which, other than LR's OLAF rig -- doesn't exist to my knowledge.

So if you stick with DXO's zany scores & rankings, all EF mount glass should launch to the top of their rankings simply because there are now more pixels behind the lenses than the D810 can muster. I rather openly want to see DXO have to eat crow by stating that the 24-70L II or 70-200 f/2.8L IS II _might be better than 835th and 1,096th best out there_, respectively. 

It's not about Canon pride or fanboyism -- it's about a comical course correction that must occur due to their absurd rankings. And one might argue they are withholding that course correction until lens testing on the A7R II is available to soften that blow.

I suppose they didn't see the need to report the lens testing so quickly -- _the 5DS is only a semi-pro camera, after all_ -- who'd want to see lens testing on that silly toy? 

- A

#dxo #fairandbalanced


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## Sporgon (Aug 31, 2015)

3kramd5 said:


> Sporgon said:
> 
> 
> > Mitch.Conner said:
> ...



It is only a rumour regarding the FF Exmor R sensor being used. As is the £2000 price tag. However the Pentax FF is a cert after the launch of the new FF lenses. 

I think they could produce one for a $2200 retail price. Would Sony want them to when theirs is $1000 more ? I expect to see the a7rII come down in price pretty quickly. 

My forecast is that the new FF Pentax will be the best value FF dslr by far when it's launched - the addition of lenses not withstanding.


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## KeithBreazeal (Aug 31, 2015)

I'll only put down my coffee and take notice when I see the Olympic and major sports photographers using Sony bodies with Canon glass.


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## ahsanford (Aug 31, 2015)

Sporgon said:


> It is only a rumour regarding the FF Exmor R sensor being used. As is the £2000 price tag. However the Pentax FF is a cert after the launch of the new FF lenses.
> 
> I think they could produce one for a $2200 retail price. Would Sony want them to when theirs is $1000 more ? I expect to see the a7rII come down in price pretty quickly.
> 
> My forecast is that the new FF Pentax will be the best value FF dslr by far when it's launched - the addition of lenses not withstanding.



People will lose it if a Pentax FF SLR comes out _because it's Pentax_. They've always been ahead of the curve on no AA, weathersealing, shockproofing, etc.

The problem is that it will have to almost be sold for a loss to get people hooked, wouldn't they? Pentax doesn't have much on the FF glass front, I thought. (Or do they have older film FF glass that they can use? I don't know much about them.) If they lack an FF lens portfolio, their value proposition will be painfully similar to the first Sony A7 models and they'll have to slash price for the first few generations until they amass more glass.

- A


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## bedford (Aug 31, 2015)

Sporgon said:


> Seriously though, if anyone thinks this BLS Exmor is significantly better than the 50 MP Canon in practice they'd better enjoy digging deep into those niches. It's a little like a Canon user repeatedly demonstrating that their 50 MP sensor has slightly more detail.......



I think overall, in photographical relevant terms the Sony Exmor sensor is about 1 stop better in low-iso dynamic range and less than 1 stop better in noise. For me hardly a reason to consider switching systems anymore (hoping this difference will also be true for the 5D IV and 6D II).

Personallly I'm currently looking more at the cost when switching to FF. And regarding the large choice of lenses for Canon (incl. Sigma and Tamron) I think Canon is probably still the best investment.

Regards,
Oliver


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## Perio (Aug 31, 2015)

Who cares?


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## sdsr (Aug 31, 2015)

ahsanford said:


> People will lose it if a Pentax FF SLR comes out _because it's Pentax_. They've always been ahead of the curve on no AA, weathersealing, shockproofing, etc.
> 
> The problem is that it will have to almost be sold for a loss to get people hooked, wouldn't they? Pentax doesn't have much on the FF glass front, I thought. (Or do they have older film FF glass that they can use? I don't know much about them.) If they lack an FF lens portfolio, their value proposition will be painfully similar to the first Sony A7 models and they'll have to slash price for the first few generations until they amass more glass.
> 
> - A



There's a huge array of vintage Pentax/Takumar lenses that could be used, many of them without an adapter and many of them very impressive, but most of them are MF, which is rather a pain on a dslr, so their appeal would likely be limited (unless the forthcoming FF body has an EVF, which would make a huge difference in that regard; I have several and use them on Sony a7 bodies, which, like other mirrorless/EVF bodies make MF easy). Some current Pentax AF lenses are old enough that they were designed for FF, but they all use slow noisy screw AF. In fact, AF hasn't been a Pentax strong-point; I've not kept up with their more recent bodies but when I switched from their then-top-of-the-line body (K5) to a 5DII (!) a few years ago I was shocked by the superiority of Canon AF in terms of speed and accuracy. Even if the new camera has better AF accuracy, they're going to lag seriously in terms of AF speed as far as many/most of their AF lenses are concerned. Those who think the mark of a good camera is its usefulness at Olympics will likely want to hold off....


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## benperrin (Sep 1, 2015)

Having used both the 5ds and owning the a7r2 I have to say that I'm bemused as to how they arrive at such conclusions. I'll say this with full disclosure; I haven't taken the a7r2 out on a proper shoot yet just tests around the house. Getting used to the mirrorless has been a challenge. The a7r2 just isn't as fast as the 5ds nor is it as reliable. Now I know that the system isn't being tested but the sensor itself. Downsampling everything to 8mp clearly disadvantages the 50mp sensor. My own real world experience shows that the 5ds files are beautiful in real life and noise wasn't a factor in my experience (I rarely leave iso100 for landscape work) even though I was at times pushing the shadows.

My conclusion in my first week of owning the a7r2 is that it definitely isn't the perfect camera like people have been saying. It is a great camera that is very capable but mirrorless has far too many flaws right now to be a better camera than the current DSLR kings. My other conclusion is to never trust test charts or companies like dxomark. Real life experience will always trump them.


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## 3kramd5 (Sep 1, 2015)

Sporgon said:


> I think they could produce one for a $2200 retail price. Would Sony want them to when theirs is $1000 more ? I expect to see the a7rII come down in price pretty quickly.



Unless Pentax is selling them as a loss-leader to get people to buy into their system.


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## 3kramd5 (Sep 1, 2015)

benperrin said:


> Downsampling everything to 8mp clearly disadvantages the 50mp sensor.



Actually, it is advantageous to the higher res sensor, in that it improves via noise-reducing averaging the dynamic range, which is the big ticket item.


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## ahsanford (Sep 1, 2015)

3kramd5 said:


> benperrin said:
> 
> 
> > Downsampling everything to 8mp clearly disadvantages the 50mp sensor.
> ...



+1. Bryan Carnathan's unabashed hard sell of the 5DS was that noise what just as good as a 5D3 when you downsample those 50 MP shots to the 5D3's native resolution.

In other words, the 5DS is a beast in the studio on or on a tripod, but if are working in low light, fear not: it's just as good as a 5D3 noisewise in high ISO, but you lose the 5DS's high res output to pull that off.

(At least that's how I read his take on the 5DS.)

- A


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## benperrin (Sep 1, 2015)

3kramd5 said:


> benperrin said:
> 
> 
> > Downsampling everything to 8mp clearly disadvantages the 50mp sensor.
> ...



Yes, it helps in terms of noise reduction for the sake of charts but even if there is slightly more noise in a 50mp file based on a per pixel level the extra detail of the 50mp opens new possibilities such as being able to push noise reduction further. It is a personal preference but I wouldn't consider something like an a7s due to the low (relatively) resolution of the sensor compared to the 5ds. There is an advantage in the real world that the resolution brings that is lost when downsampled to 8mp. Now for plenty of people the a7s has more than enough resolution which is great but to dismiss a 50mp camera based on dxomarks methods is ludicrous at best. Having said that most people probably don't need or want 50mp at this time.


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## Aglet (Sep 1, 2015)

sdsr said:


> ahsanford said:
> 
> 
> > People will lose it if a Pentax FF SLR comes out _because it's Pentax_. They've always been ahead of the curve on no AA, weathersealing, shockproofing, etc.
> ...



I think Pentax has about 9 lenses in their current catalog that are FF compatible, most being old film era primes.

you can see them here:

http://ricoh-imaging.ca/en/products/lenses/

The the D FA series, for digital-optimized
and the FA & FA Limited series (but not FA 645)

I hope they also enable a crop mode to use the DA (crop) series glass too.
BUT, if you're a real Pentaxian, you've been collecting old FF film era glass for the past few years so you'll have something to use on the new FF Pentax body when it arrives.


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## jrista (Sep 1, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*



LOALTD said:


> How has this not been posted yet? Forgive and delete if it has:
> 
> 
> http://www.dxomark.com/Cameras/Sony/A7R-II
> ...



The D810 has about a stop more DR than the A7R-II at the lowest ISOs (64/32), which is actually pretty amazing. Remember, dynamic range is *powers of two*. They also somehow eeked more FWC out of the same 36.3mp sensor. Not sure how they did that. 



No one should be surprised that the Sony scores better than the 5Ds. Until Canon reduces their read noise, that will always be the case. That said, the 5Ds does have better noise characteristics, and in a couple tests I did, it definitely supported a bit more shadow pushing than any prior Canon camera. It still had the classic Canon color blotch, but it was a bit more neutral-colored, rather than heavily red. I did not see any banding either. I thought that was nice. 

If I was doing landscape photography, I still wouldn't pick a Canon camera, but the 5Ds should perform well for most things.


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## 3kramd5 (Sep 1, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*



benperrin said:


> 3kramd5 said:
> 
> 
> > benperrin said:
> ...



Within the DXO scoring methodology, downsampling helps, and the more you downsample the better. For whatever reason they don't consider sensor resolution in their camera scores, and instead consider it in their lens scores.


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## jrista (Sep 1, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*



3kramd5 said:


> benperrin said:
> 
> 
> > 3kramd5 said:
> ...



Downsampling always helps, not just with DXO. Downsampling averages pixel data together, which improves signal strength and reduces noise. That will always improve DR. Same reason why stacking multiple frames together when doing astrophotography improves signal strength and reduces noise.


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## that1guyy (Sep 1, 2015)

Perio said:


> Who cares?



You sound mad.


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## 3kramd5 (Sep 1, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*



jrista said:


> 3kramd5 said:
> 
> 
> > benperrin said:
> ...



Down sampling always helps... if noise and DR are your metrics.


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## that1guyy (Sep 1, 2015)

*Inserts some stupid sarcastic deriding Sony*
*inserts : face

*feels accomplished*


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## 3kramd5 (Sep 1, 2015)

that1guyy said:


> *Inserts some stupid sarcastic deriding Sony*
> *inserts : face
> 
> *feels accomplished*



Meh, I don't need to defend them. They have $3200 of my money, minus NRE, components, production, shipping, and dealer cut.


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## George D. (Sep 1, 2015)

Conclusion: 5D4 is expected to have DR on a par with competition. Meanwhile we need a same sample image of EF35mm 1.4L II shot with a 5DS and a A7RII for the record. 

With all this testing I just realized there's room for another category: Nikon cameras with Canon lenses. Surpass the DxO mark 8).


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## moreorless (Sep 1, 2015)

One ironic thing of course is that it looks like Sony has sacrifed based ISO DR for higher ISO DR, about half of the advantage the 36 MP sensor had at ISO 100 over Canon is gone.

As a Nikon shooter who might well have the chance to buy this sensor in the future I have to say that its performance really doesn't live up to the "game changer" hype, the same as that Samsung 28 MP APSC one. You look back a generation and the D800 sensor was a MUCH bigger improvement in performance over the previous gen(Canons 21 MP, Nikon's 12 and 24 MP). Resolution increased by 50% over Nikons previous best and by 200% over the camera with a similar market position, DR increased and general noise performance was half a stop better.

Sony really missed the boat not getting that sensor in one of their bodies first IMHO although I spose that likely comes an a premium which given there smaller sales probably explains the massive jump in the A7R II price.


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## StudentOfLight (Sep 1, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*



jrista said:


> 3kramd5 said:
> 
> 
> > benperrin said:
> ...


Perhaps I don't understand downsampling and how averages work, but I constructed a simple experiment using excel. (see attached)

I took a black frame with a hypothetical 16 pixel camera. i.e. A perfectly accurate camera would take an image with a 0 value for each pixel. I then introduced a random noise value for each pixel. I then added pixels together first 2 pixel arrays then 4 pixel arrays then averaged to get the image noise. It appears the average image noise is the same regardless of how I scale the image down. Am I doing something wrong?


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## Sporgon (Sep 1, 2015)

3kramd5 said:


> Sporgon said:
> 
> 
> > I think they could produce one for a $2200 retail price. Would Sony want them to when theirs is $1000 more ? I expect to see the a7rII come down in price pretty quickly.
> ...



Possibly. Pentax have done that type of thing before: the 50mm f/1.4 eight element lens that cost more to manufacture than they sold it for, produced to raise them to the perceived level of Zeiss. And the Pentax genes do still seem to be alive in the latest digital cameras despite now being owned by Ricoh. 

Regarding lenses, they do have a few FF 'limited' (high quality) primes and have just introduced two top end FF zooms.

For us Canon (and Nikon) FF dslr users who don't use the top tier cameras Pentax producing a FF dslr is very good news. It will be a feature rich camera for a good price and will keep the likes of the 6D and Nikon D610 ( or is it D630 by now ?) on their toes and keen on price. 

Despite being a BLS I don't see why after development costs the R sensor will be much more expensive than the other 36 mp one. Having had a play with a Sony a7RII recently I think Sony are yanking the chain on the price. It seems to me that the major steps forward in the a7rII over the a7r is everything_ but_ the sensor itself.........


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## romanr74 (Sep 1, 2015)

privatebydesign said:


> We all refer to DXO on occasions...



No we don't...


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## privatebydesign (Sep 1, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*



StudentOfLight said:


> jrista said:
> 
> 
> > 3kramd5 said:
> ...


You are not averaging, you are adding, to get the lower noise you have to divide by the number of pixels you have added together, in this case four. Take any one pixel of information and it has to fit in the bit depth, for 14 bit that is 16,385, if you add four together you can't have a number higher than 16,385, so you have to divide by that same number to keep your range constant.

So take your last block of four, if noise becomes visible, your noise floor, at 3 (for example) you have two noisy pixels px-ID-14 and px-ID-15, if you add the four together you get 8, then divide by four you get 2 per pixel, which you can't see. Voila, two pixels that had visible noise don't now have visible noise, but you have lost the ability to differentiate detail in those four pixels so you now have one noiseless pixel instead of two of four noisy ones.

To be sure, your DR has not increased in that you don't have a wider range, you can't see below your noise floor and the bit depth has not increased because add four and divide by four is a zero sum when confined to whole numbers. You have lowered the noise levels by averaging/downsampling though.


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## romanr74 (Sep 1, 2015)

sdsr said:


> ahsanford said:
> 
> 
> > People will lose it if a Pentax FF SLR comes out _because it's Pentax_. They've always been ahead of the curve on no AA, weathersealing, shockproofing, etc.
> ...



I have a terribly hard time to believe that these film area lenses will perform sufficently well on such high resolution sensors...


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## StudentOfLight (Sep 1, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*



privatebydesign said:


> You are not averaging, you are adding, to get the lower noise you have to divide by the number of pixels you have added together, in this case four. Take any one pixel of information and it has to fit in the bit depth, for 14 bit that is 16,385, if you add four together you can't have a number higher than 16,385, so you have to divide by that same number to keep your range constant.
> 
> So take your last block of four, if noise becomes visible, your noise floor, at 3 (for example) you have two noisy pixels px-ID-14 and px-ID-15, if you add the four together you get 8, then divide by four you get 2 per pixel, which you can't see. Voila, two pixels that had visible noise don't now have visible noise, but you have lost the ability to differentiate detail in those four pixels so you now have one noiseless pixel instead of two of four noisy ones.
> 
> To be sure, your DR has not increased in that you don't have a wider range, you can't see below your noise floor and the bit depth has not increased because add four and divide by four is a zero sum when confined to whole numbers. You have lowered the noise levels by averaging/downsampling though.


Hi PBD, thanks for the reply.

I don't know if I'm just retarded, but I still don't get it. I included a division process in the averaging my original spreadsheet here is an update I just changed the layout to put the averages in at the bottom of the table (see attached)

Is my concept of average image noise flawed (i.e. Average image noise = sum of pixel noise divided by number of pixels)


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## sdsr (Sep 1, 2015)

romanr74 said:


> I have a terribly hard time to believe that these film area lenses will perform sufficently well on such high resolution sensors...



It all rather depends on what you mean by "sufficiently well". If you mean the sort of technical near-perfection of a Zeiss Otus, maybe not, but some come close to a degree you might find surprising (the hyper-critical Otus fan Ming Thein, for instance, is a big admirer of the Contax/Zeiss series from the 1970s-90s; being able to use them is among the advantages he gives for the Canon 5DS line and, especially, the Sony a7rII). With fast lenses wide open you might often find plenty to complain about, but often minor stopping down makes them indistinguishable from good modern lenses, while their "flaws" wide open can add a degree of character/atmosphere that for certain sorts of photography is (for some of us, anyway) highly desirable. I use such lenses on my a7r/a7rII more than any other (it also doesn't hurt that they're often a pleasure to handle regardless of image quality, including the older Pentax/Takumars). There are lots of examples on-line of images taken with so-called legacy lenses on cameras with high-resolution sensors, both dslrs and mirrorless (where they're easier to use), including comparisons of vintage vs new.


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## 3kramd5 (Sep 1, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*



StudentOfLight said:


> snip



I claim zero expertise with respect to signal processing, so I'm probably wrong, but:

It seems that you're treating everything as if it's noise, or everything as if it's signal. The total reading in any given pixel is both noise AND signal. If you consider them independently, when you average multiple pixels, both values will decrease, but noise will decrease more than signal.


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## sdsr (Sep 1, 2015)

Sporgon said:


> It seems to me that the major steps forward in the a7rII over the a7r is everything_ but_ the sensor itself.........



It seems that way to me, too - I moved up to an a7rII for the IBIS, silent shutter, vibration-fix etc. rather than for the sensor (indeed, the sensor isn't what attracted me to this line in the first place - I prefer mirrorless/EVF and FF and at the time Sony was the only company providing both), though it seems to me that the high ISO performance of the a7rII is somewhat better than the a7r's. (Of course, if it's true, as some are reporting, that the problem Leica etc. wide-angle M mount lenses work better on the a7rII, that will presumably be a big deal for those wanting to use such lenses.)


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## bdunbar79 (Sep 1, 2015)

Remember, Noise = SQRT #photons

So Noise = SQRT"signal"

Signal adds linearly while noise adds only in quadrant. Signal adds faster than noise can. The more signal you have, of course the more total noise you have, but you gain signal faster than noise increases.


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## privatebydesign (Sep 1, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*



StudentOfLight said:


> privatebydesign said:
> 
> 
> > You are not averaging, you are adding, to get the lower noise you have to divide by the number of pixels you have added together, in this case four. Take any one pixel of information and it has to fit in the bit depth, for 14 bit that is 16,385, if you add four together you can't have a number higher than 16,385, so you have to divide by that same number to keep your range constant.
> ...



Yes, you don't average the first group.

So take your first four pixels, say the noise floor is 4, ID-2 and ID-4 are both noisy pixels, at 100% view those pixels are garbage. Add the four together and divide by four and the resulting value is 3, so that block of four pixels, that is now one number is no longer noisy, at 100% view that down sampled one pixel (the four have become one) is not noisy but the picture is 1/4 the size it was.

This is how multiple exposures reduces noise on a same size basis, take various exposures of the same thing, add them together and divide by the number of exposures and you get less noise and retain the number of pixels. Basic astrphotography.



> Is my concept of average image noise flawed (i.e. Average image noise = sum of pixel noise divided by number of pixels)



Yes this concept is wrong. Remember, you are not adding up all the values and dividing by the total number of pixels, you are only adding the down sampled pixels together and dividing by that number of pixels to get a new averaged pixel value. Then the number of actual pixels that fall into the range of noise is lower, but so is detail!

P.S. You can't have decimal places in your averages (you'd need more bit depth), so in the adjusted table below the .5 and above would be rounded up, .49 and lower would be rounded down. So you'd actually have 6 - 3 - 1.


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## StudentOfLight (Sep 1, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*



privatebydesign said:


> StudentOfLight said:
> 
> 
> > privatebydesign said:
> ...


I've ask the question before in a different thread regarding how "noise floor" is calculated but unfortunately got no reply. I thought that since this example is a dark frame that the average value of all the "supposed-to-be-zero-value pixels" would be the noise floor. Hence I calculated the average value of 2.5 initially.


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## privatebydesign (Sep 1, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*



StudentOfLight said:


> privatebydesign said:
> 
> 
> > StudentOfLight said:
> ...



My understanding is that noise floor is a comparatively arbitrary figure given as a percentage of signal. That is, anything below X value and above 0 is noise, so in your examples above it would be more accurate to say anything any pixel value between 1 and 3 would be considered noisy, but the averaging works just the same, you get less noisy pixels and fewer of them. So in the imaginary simplified version we are using 0 is black, 4 is the darkest grey you can discern, 1-3 are just noise.

Forgive me for keep having edited my above reply whilst you were replying to it!


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## bedford (Sep 1, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*



StudentOfLight said:


> I've ask the question before in a different thread regarding how "noise floor" is calculated but unfortunately got no reply. I thought that since this example is a dark frame that the average value of all the "supposed-to-be-zero-value pixels" would be the noise floor. Hence I calculated the average value of 2.5 initially.



The noise is not the average value, but the arbitrary deviation of the values.

If you calculate the relevant statistical values for your example:
Number of pixels 16 ==> avg = 2,5; standard deviation = 2,221
Number of pixels 8 ==> avg = 5; standard deviation = 2,268
Number of pixels 4 ==> avg = 10; standard deviation = 3,65 (althoug not very meaningful, because the number of pixels is too low)

Average calculates as (sum of values)/(number of values).

Now, if you take avg/StdDev as measure for the signal-to-noise ratio you will see, that the lower the number of pixel the higher the SNR.

Oliver


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## 3kramd5 (Sep 1, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*



StudentOfLight said:


> privatebydesign said:
> 
> 
> > StudentOfLight said:
> ...



It's very commonly defined as SNR=1


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## bwana (Sep 2, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*



StudentOfLight said:


> jrista said:
> 
> 
> > 3kramd5 said:
> ...


I see the add but where is the average?

bwa


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## romanr74 (Sep 2, 2015)

sdsr said:


> romanr74 said:
> 
> 
> > I have a terribly hard time to believe that these film area lenses will perform sufficently well on such high resolution sensors...
> ...



Can you share one or two links?


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## StudentOfLight (Sep 2, 2015)

Thanks for the replies guys.


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## sanj (Sep 2, 2015)

that1guyy said:


> *Inserts some stupid sarcastic deriding Sony*
> *inserts : face
> 
> *feels accomplished*



Hahahahah. So true.


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## 3kramd5 (Sep 24, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*



3kramd5 said:


> dilbert said:
> 
> 
> > bmwzimmer said:
> ...




And we will never know. Per a DxO post on their website, they won't re-test it.


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## East Wind Photography (Sep 25, 2015)

ahsanford said:


> You've got to love DXO's Fox News-ness about their shtick. Amazing.
> 
> Number of Canon lenses retested on the 5DS? *Zero.* They wouldn't want the world's 1,064th best lens -- _the Canon 70-200 f/2.8L IS II_ -- suddenly becoming the world's 20th best lens all of sudden.
> 
> ...



Forget about the sensor...how does that Sony perform in the rain? I'd like to see the scores on that.


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## jrista (Sep 25, 2015)

*Re: Sony A7R II scores 98, new king of DxO Mark (by a nose)*



StudentOfLight said:


> I've ask the question before in a different thread regarding how "noise floor" is calculated but unfortunately got no reply. I thought that since this example is a dark frame that the average value of all the "supposed-to-be-zero-value pixels" would be the noise floor. Hence I calculated the average value of 2.5 initially.



There is actually a very specific process you go through, using bias, dark and flat frames, to calculate system gain, and once you have gain, calculate read noise and dark current. You have to account for bias offset in order to actually measure the actual standard deviation of noise, so getting proper bias frames is important. Getting proper flat frames is also important as they are essential to calculating gain. Depending on what you want to know about dark current, whether you want to know anything at all, you may need to take quite a few dark frames, and in a very meticulous fashion in order to avoid oscillating temperatures between dark frames and the like.

When it comes to cameras with bayer arrays, you need to account for that as well. Most CFA cameras will give you very bad results if you don't extract one color channel from the NON-demosaiced (non-interpolated) RAW data. Usually green is used. 

If you really want to calculate gain, read noise, dark current, etc. you can follow this procedure:

http://www.stark-labs.com/craig/articles/assets/CCD_SNR3.pdf

Follow it to the letter, and you should get fairly accurate results.


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## scottkinfw (Sep 25, 2015)

Well I'll just wipe off my poopy 5DIII and get a new a7r II- not!


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