# DXO finally re-tests EF lenses on the 5DS R



## ahsanford (Nov 30, 2015)

This just dropped:
http://www.dxomark.com/Cameras/Canon/EOS-5DS-R---Lenses-tested

They have published their testing of EF lenses on the 5DS R for the first time. No testing on the 5DS that I can see (yet). But this represents a good 100+ EF lenses retested in a 50 MP context, so love or hate DXO, I think you'll be hard pressed to find another site so comprehensively trying to answer the questions of "How much of the 50 MP will my lens actually 'see'?" or "Is my lens future-proofed for the high MP world?"

None of the rankings or 'lens selector' doo-dads or lens baseball cards report the new scores, but if you choose a lens and select the body it's on as the 5DS R, the new scores are there.

- A


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## ahsanford (Nov 30, 2015)

Some interesting selections:

*Canon 35L II*
5DS R = 37 P-MPix / 42 Overall Score 
5D3 = 18 P-MPix / 33 Overall Score 

*Sigma 35 Art*
5DS R = 34 P-MPix / 41 Overall Score 
5D3 = 19 P-MPix / 34 Overall Score 
_
(so apparently, the absurd average-hurting softness of the Canon @ f/22 vs. the Sigma tapping out at f/16, which rated the Art higher than the L, were overcome with pixels this time...)_

----------------

*Canon 50L*
5DS R = 21 P-MPix / 35 Overall Score 
5D3 = 16 P-MPix / 29 Overall Score 
_
(very crudely from just the sharpness overall metric, this implies the 50L doesn't benefit from all those pixels as much as sharper lenses might, which should not be surprising)_

*Zeiss 55 Otus*
5DS R = 37 P-MPix / 46 Overall Score 
5D3 = 21 P-MPix / 38 Overall Score 

*Sigma 50 Art*
5DS R = 40 P-MPix / 44 Overall Score 
5D3 = 21 P-MPix / 35 Overall Score 
_
(first ever report of the Art outresolving the Otus?)_

- A


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## ahsanford (Nov 30, 2015)

But DXO is still DXO. 

Classic.


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## bdunbar79 (Nov 30, 2015)

Boy that 300mm f/2.8L II IS lens sure seems like a truly perfect lens, huh? That is incredible.


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## ahsanford (Nov 30, 2015)

If curious -- DXO's P-MPix sharpness assessment of how much of the 50 MP sensor is realized by these lenses:

Canon 11-24L = 26
Sigma 20mm Art = 40
Canon 16-35 f/4L IS = 23
Canon 24-70 f/2.8L II = 32
Canon 24-70 f/4L IS = 21
Sigma 24 Art = 30
Sigma 24-35 Art = 32
Canon 35 L II = 37
Canon 35 f/2 IS USM = 34
Sigma 35 Art = 34
Canon 50L = 21
Sigma 50 Art = 40
Zeiss 55 Otus = 37
Canon 70-200 f/2.8L IS II = 33
Tamron SP 70-200mm F/2.8 Di VC USD = 36
Canon 85L I = 30
Canon 85L II = 23
Zeiss 85 Otus = 41
Canon 100L = 24 (this may be because it stops down to f/32, which crushes its average)
Canon 100-400L II = 24
Canon 135L = 30
Canon 200-400 no extender = 33
Canon 200-400 with extender = 18
*Canon 300 f/2.8L IS II = 45* (highest they've ever reported)
Canon 500L II = 31
Canon 600L II = 37

Shaded in red are where other non-DXO tests, general reputation, etc. would question those numbers. That 16-35 f/4L IS figure, in particular, would go against the grain of virtually every review.

Feel free to mine the original link at the top -- something you may have wanted compared on 50 MP is probably on there.

- A


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## ahsanford (Nov 30, 2015)

And, unless I've read something incorrectly, despite have +14 MP over the D800E, only the Zeiss 135mm on a 5DS R will crack DXO's top five lens + body combos. So slapping the same damn Sigma Art or Zeiss Otus lens on that 5DS R will do you no better than the D800E.

If you're shocked at that, just remember who's reporting the data. :

- A


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## ahsanford (Nov 30, 2015)

Also, another peach from what they released today.

Apparently, everything else being the same -- except the Canon vignetting a shade more yet outresolving the Nikon -- the Nikon gets the higher score.

So, now, after a few years of the same lens being world class or disappointing depending on how many pixels were sitting behind it no longer applies. _It's all about the vignetting, people._ Brighter corners are the new megapixels.

#dxo #fairandbalanced

- A


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## Proscribo (Nov 30, 2015)

ahsanford said:


> Also, another peach from what they released today.
> 
> Apparently, everything else being the same -- except the Canon vignetting a shade more yet outresolving the Nikon -- the Nikon gets the higher score.
> 
> ...


I would say that it's more thanks to the Awesome Dynamic Range provided by those Awesome Sony Sensors!

Not like it would have *anything* to do with lens performance, but still..


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## 3kramd5 (Nov 30, 2015)

Proscribo said:


> ahsanford said:
> 
> 
> > Also, another peach from what they released today.
> ...



Correct, DXO uses sensor DR in their lens scoring algorithm scheme.



bdunbar79 said:


> Boy that 300mm f/2.8L II IS lens sure seems like a truly perfect lens, huh? That is incredible.



Quite!


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## ahsanford (Nov 30, 2015)

Their databases haven't updated, but you can you select the 5DS R on the lens tested tab. 

I can't link it as it's not URL-discrete, but I snagged a few screenshots. The first is sorted on overall score and the second is sorted on sharpness. 

(The boxed number under the score/value equals their global ranking at the site across all mounts / designs.)

1) Three Zeiss + one Sigma lens on the 5DS R cracked their top 10 for ratings.

2) Not surprisingly, the 9 sharpest lenses they have tested all came on the 5DS R.

- A


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## Maximilian (Nov 30, 2015)

Once again:

*DxO*:

*D*o optical measurments and get data for your SW.
E*x*it writing reviews and rankings.
*O*ptimize you products.

That will increase your reputation and profit much more than the *b*iased *s*cores you do now.


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## ahsanford (Nov 30, 2015)

Maximilian said:


> Once again:
> 
> *DxO*:
> 
> ...



Unfortunately, they are the biggest show in town and we may be stuck with them. Consider: PhotoZone and LensTip have tested a combined total of two lenses on the 5DS / 5DS R to date.

- A


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## chromophore (Dec 1, 2015)

ahsanford said:


> Maximilian said:
> 
> 
> > Once again:
> ...



DxO only has as much credibility as photographers are willing to give them. Consequently, the innumeracy of the photographic community as a whole, and the way popular online photo sites and blogs (PetaPixel being one I can think of for example) announce DxO results, only reinforce DxO's position as a source for information about how bodies and lenses perform. When is the last time you saw PetaPixel talk about PZ or LensTip or TDP measurements? But DxO crowns a new sensor or lens, it gets front page news despite their methodology being complete BS.

And that is the fault of photographers who don't know basic statistics or who don't care to know. They just want some number they can spout as if it were gospel. That is the fault of people who repost DxO results on photo forums as if they were the least bit meaningful. That is the sort of behavior that gives DxO the exposure and the attention it wants.

Even the criticisms (this one included) only serve to draw more attention to their testing. No news is bad news: like political candidates, controversy is good--it serves to further polarize opinions, and those who disagree or point out even the most elementary methodological flaws, are conveniently branded as biased and their evidence casually dismissed. It is no different than trying to debunk flat earth theorists with science.

Photographers as a whole *choose* to be ignorant. For all their attention to MTF curves and the minutiae of sensor technology, as a group, they don't really care to think critically. Flame me all you want. Not everyone is like that. But the ones who do care are a small minority. Most photographers have a hard enough time figuring out f-stops, never mind asking actual mathematics like 95% confidence intervals for the mean MTF at 40 lp/mm.


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## LSXPhotog (Dec 1, 2015)

ahsanford said:


> But DXO is still DXO.
> 
> Classic.


This is ABSOLUTE and total proof of DxO manipulating overall scores to meet their goals and agenda. Outscored in every category....but it's mounted to a Canon...deduct 10-points.

What a shame. They have within their power to create a fair system but choose to not even hide their bias...the DxO One Camera was hilarious. 'Offers super resolution mode where it combines several images to create a cleaner image...something many other cameras do, but we won't test any of them for that.'


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## Maximilian (Dec 1, 2015)

ahsanford said:


> ...
> _It's all about the vignetting, people._ Brighter corners are the new megapixels.
> ...


Could anyone please tell me how the vignetting of a lens could differ by the type of FF sensor sitting behind it???   
That's absolute rubbish. If not corrected by SW vignetting will stay the same for the same optical formula.

5Ds/R sensor size: 36 mm x 24 mm
D810 sensor size: 35.9 mm x 24 mm

Please don't tell me it's about this 0.1 mm. And please don't tell me Zeiss and Sigma have a different optical design for Canon and Nikon. 
RUBBISH.


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## Proscribo (Dec 1, 2015)

Maximilian said:


> ahsanford said:
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Smaller pixels. I'd think the vignetting here isn't caused by the lens but rather the sensor.


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## privatebydesign (Dec 1, 2015)

Maximilian said:


> ahsanford said:
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> ...



I was wondering that earlier, I came to the conclusion that it is down to the microlens array and filter stack on top of the sensor. We all agree DxO come up with some very fishy numbers, but their core business is selling lens correction software and I believe those figures.

Now I am not saying that what they say is the whole truth, for instance where is the 'corner' measured from, etc, but I do believe they have to take an accurate measurement of the vignetting to make their lens corrections valuable, and they are very good from what I have seen.


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## Maximilian (Dec 1, 2015)

Maximilian said:


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





Proscribo said:


> Smaller pixels. I'd think the vignetting here isn't caused by the lens but rather the sensor.





privatebydesign said:


> I was wondering that earlier, I came to the conclusion that it is down to the microlens array and filter stack on top of the sensor.



Thanks, guys, for helping me with this. I didn't come up with these ideas but I think they're the right explanation.
But still it's interesting that this vignetting seems to have a much higher influence to the scores as the resolution has (now?!). 
And still it's difficult for me as technican we're not measuring the lens itself but more or less the sensor behind it *sigh* 
No, better say the whole combination. And therefore a solitary DxO scoreboard for lenses over different camera brands or even bodies is not worth a cent. 

Conclusion for DxO scores:
You can only compare lenses with the same camera body. 
Or you can use it to compare different bodies within a brand with the same lens.
Or you can compare different brands with a third party lens. 

Conclusion for myself:
Go shooting! Forget about DxO scores!


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## justaCanonuser (Dec 1, 2015)

What really amazes me is that Canon's EF 1.2/85 II with 38 P-Mpx (whatever P-Mpx is) turns out to be sharper than the classic Zeiss 1.4/85 with 33 P-Mpx. The Otus of course is with 47 P-Mpx much sharper, as expected. 

In real life I am always am impressed by the results my EF 85/1.2 can deliver, in particular this special blend of decent in-focus sharpness and creamy bokeh. This is the first time I find my own real life experience reflected in DxO lab data. Canon really did a great job with that monster of a superfast lens!


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## justaCanonuser (Dec 1, 2015)

Maximilian said:


> Conclusion for myself:
> Go shooting! Forget about DxO scores!



+1 ... Soon I go shooting and forget about DxO by myself ;D


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## BRunner (Dec 1, 2015)

Well, DXO as most of other sites gives us bunch of numbers, how all lenses perform at near field distance at flat target... Don't know how often you do art reproduction or shot brick walls... 
I'm interested in performance at macro distances with macro lenses, in infinity performance with almost all lenses, at longer distances with tele-lenses and so on...

Nice example is Zeiss Distagon 2.8/25 ZF, which is optimized for infinity performance at f8-f11. At this settings is one of the best lenses in this FL, yet in all tests it's flop. On the other side, new Zeiss Distagon 2/25 Z* is fantastic at close distances, superior in all tests, but at infinity it never reaches corner performance of it's slower sibling... And DXO can describe all this nuances with ONE NUMBER!


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## StudentOfLight (Dec 1, 2015)

The difference in identical-lens performance on camera A and camera B is predominantly due to ISO performance. A 1stop difference equates to 15pt.
pt = Log2((ISO_A)/(ISO_B)) x(15)

Substituting the ISO scores for D800E (2979) & 5Ds-R (2308)
pt = Log2((2979)/(2308)) x(15)
= 5.52

So identical optical formulas on D800E start with +5.52 more than the 5Ds-R due to noise.


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## jd7 (Dec 1, 2015)

chromophore said:


> DxO only has as much credibility as photographers are willing to give them. Consequently, the innumeracy of the photographic community as a whole, and the way popular online photo sites and blogs (PetaPixel being one I can think of for example) announce DxO results, only reinforce DxO's position as a source for information about how bodies and lenses perform. When is the last time you saw PetaPixel talk about PZ or LensTip or TDP measurements? But DxO crowns a new sensor or lens, it gets front page news despite their methodology being complete BS.
> 
> And that is the fault of photographers who don't know basic statistics or who don't care to know. They just want some number they can spout as if it were gospel. That is the fault of people who repost DxO results on photo forums as if they were the least bit meaningful. That is the sort of behavior that gives DxO the exposure and the attention it wants.
> 
> ...



I'm not going to flame you - I'm going to agree with you. And sadly, photographers are far from the only group which can be accused of not thinking critically.


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## StudentOfLight (Dec 1, 2015)

jd7 said:


> chromophore said:
> 
> 
> > DxO only has as much credibility as photographers are willing to give them. Consequently, the innumeracy of the photographic community as a whole, and the way popular online photo sites and blogs (PetaPixel being one I can think of for example) announce DxO results, only reinforce DxO's position as a source for information about how bodies and lenses perform. When is the last time you saw PetaPixel talk about PZ or LensTip or TDP measurements? But DxO crowns a new sensor or lens, it gets front page news despite their methodology being complete BS.
> ...


+2

The fundamental assumption of shooting with 150lux and the subsequent weighting of T-Stop and vignette leads to nonsensical results like this:
http://www.dxomark.com/Lenses/Compare/Side-by-side/Zeiss-Carl-Zeiss-Apo-Planar-T-Star-Otus-85mm-F14-ZF2-Nikon-on-Nikon-D700-versus-Canon-EF-500mm-F4L-IS-II-USM-on-Canon-EOS-5D__1384_441_393_176

and this:
http://www.dxomark.com/Lenses/Compare/Side-by-side/EF50mm-f-1-8-II-on-Canon-EOS-5DS-R-versus-Canon-EF-600mm-F4L-IS-II-USM-on-Canon-EOS-5DS-R__187_1009_394_1009

etc...


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## 3kramd5 (Dec 1, 2015)

StudentOfLight said:


> The fundamental assumption of shooting with 150lux and the subsequent weighting of T-Stop and vignette leads to nonsensical results like this:
> http://www.dxomark.com/Lenses/Compare/Side-by-side/Zeiss-Carl-Zeiss-Apo-Planar-T-Star-Otus-85mm-F14-ZF2-Nikon-on-Nikon-D700-versus-Canon-EF-500mm-F4L-IS-II-USM-on-Canon-EOS-5D__1384_441_393_176
> 
> and this:
> http://www.dxomark.com/Lenses/Compare/Side-by-side/EF50mm-f-1-8-II-on-Canon-EOS-5DS-R-versus-Canon-EF-600mm-F4L-IS-II-USM-on-Canon-EOS-5DS-R__187_1009_394_1009



The Otus 85 and the EF500 II are as similar as spectacles and binoculars. It not just that the weighting leads to nonsensical results, the decision to derive a score with no consideration of purpose is nonsense in and of itself. 

Shrug. I agree with PBD: DxO's bread and butter is (or at least was in the past, now that they're a camera manufacturer their focus may shift, pun intended) lens measurements and software-side corrections thereof. The aggregate scores exist to drive web traffic, but the underlying data are pretty good.


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## StudentOfLight (Dec 1, 2015)

dilbert said:


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


I choose option d) Dig, investigate and use my brain because I don't need an expert to tell me what to think.

Here are more details: http://www.dxomark.com/About/Lens-scores


> DxOMark Score is based on low-light conditions (150 lux and 1/60s exposure time). We chose these conditions because we believe low-light performance is very important in photography today, and because photographers need to know how well lenses perform at their widest aperture. Lenses with a high f-number are usually more expensive, so photographers want to know if the performance is worth the expense. The score does not account for depth of field, and only considers performance at best focus.


e.g. Given 150 lux and 1/60s,
- Lens A with T5.6 needs to shoot ISO 3200 on camera X for a proper exposure. 
- Lens B with T1.4 needs to shoot ISO 100 on camera Y for a proper exposure. 

The difference between AX and BY is highly dependent on ISO performance of Camera-X vs ISO performance of Camera-Y, and not so much about lens performance X vs lens performance Y. I wonder how noticeable the difference between ISO 3200 and ISO 100 is... ???

Here is the classic example a world class f/4 lens vs an ultra-wide aperture lens:
http://www.dxomark.com/Lenses/Compare/Side-by-side/Canon-EF-600mm-F4L-IS-II-USM-on-Canon-EOS-5DS-R-versus-EF50mm-f-1.2L-USM-on-Canon-EOS-5DS-R__394_1009_197_1009
The 600mm f/4 is significantly better in every metric except T-stop. So the only way for it to score lower than the 50/1.2 is if T-stop is valued much more than any of the other metrics. Surely this points out the problem in the most obvious way. 

On to the actual value of 150 lux. I can't speak for others there, but I hardly ever shoot in 150 lux light levels. If I do, it wouldn't be by choice, it would usually be the very the last resort.

FYI for more info on lux: https://en.wikipedia.org/wiki/Lux (150 lux = 1/60s at T1 at ISO 100. This is something like a dimly lit church.)

Is the typical photographer always/predominantly interested in shooting in 150 lux? Also take into account the fact that depth-of-field for different use cases will require you stopping down and for sports you might want to use faster shutters speeds to stop motion. Again, I cannot speak for others out there but I'll answer for the following use cases given 150 lux:
- Portrait Photography? (e.g. T5.6, 1/60s therefore ISO 3200) - No, I add light to shoot at low ISO
- Landscape Photography? (e.g. T8, 1/60s therefore ISO 6400) - No (refer to table in Wikipedia article)
- Commercial photography? (e.g. T5.6, 1/60s therefore ISO 3200) - No, use good lighting and ISO
- Wildlife Photography? (e.g. T5.6, 1/2000s therefore ISO 51200) - No, I call it a day when the sun sets.
- Events photography? (e.g. T4, 1/250s therefore ISO 6400) - Preferably not, I add light when possible
- Wedding photography? (e.g. T4, 1/250s therefore ISO 6400) - Preferably not, I add light when possible
- Sports photography? (e.g. T4, 1/2000s therefore ISO 25600) - Preferably not, but sometimes it's unavoidable
- Astro-photography? (e.g. T2.8, 1/60s therefore ISO 800) Yes, this is the one case where I definitely shoot with much lower light levels.

Do those ISO values reflect real world shooting? 

Whenever possible, would a professional not negotiate with relevant stakeholders to organize a better lighting setup or the ability to use flash for the client's images if there was 150 lux ambient? Forget about pro's for a second, green-box shooters will also have the pop-up flash activating automatically when the light levels drop low, so yet again the 150 lux assumption goes out the proverbial window as the pop-up flash will illuminate the subject instead of relying on low ambient light.

Do you really still think 150 lux is a reasonable assumption to apply for overall lens ranking? Surely it is a very specialize use case which does not apply to typical shooting scenarios. Also sports photography, being a possible 150 lux use case would not automatically lean towards an Otus 85mm f/1.4 (manual focus prime lens) for their low light conditions simply due to it's fast T-stop. The Canon EF 200-400mm f/4 L IS USM would be much more appropriate and useful due to reach, autofocus, zooming (to optimize framing) and image stabilization.

Surely lenses should be ranked by use case, and not by one overall number which is heavily influenced by T-stop due to an arbitrary 150 lux constraint.

TL/DR: In summary I will be so audacious as to quote myself:


> The fundamental assumption of shooting with 150lux and the subsequent weighting of T-Stop and vignette leads to nonsensical results...


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## ahsanford (Dec 1, 2015)

I personally think 90% of DXO haters will evaporate simply by dropping the aggregate lens score and the cross-platform lens + body rankings. Just report your test data and walk away, i.e. limit yourself to just being a resource and a not a source of opinion.

- A


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## privatebydesign (Dec 1, 2015)

ahsanford said:


> I personally think 90% of DXO haters will evaporate simply by dropping the aggregate lens score and the cross-platform lens + body rankings. Just report your test data and walk away, i.e. limit yourself to just being a resource and a not a source of opinion.
> 
> - A



And that won't happen. 

The ridicule is a good source of clicks and links and page hits. We are in the age where the Kardashians can become multi millionaires on the back of a 'leaked' porn movie, and DxO can keep their name in the photography headlines by publishing biased sudo science bull.


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## IglooEater (Dec 2, 2015)

Maximilian said:


> ahsanford said:
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Coming from DXO causes me to simply assume it's wrong. However, I could believe it from almost anyone else. I'm guessing that more pixels and/or less effective microlenses, and/or deeper pixel wells, and/or something else, could have an effect on the amount of light *measured* at a high angle of incidence - i.e. the corners- thus causing more apparent vignetting on one sensor than on another.


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## candc (Dec 2, 2015)

The thing I am most I am most interested in on the dxo site is the p-mpix measurement but I am not sure how exactly they measure it? This is what I can find on their website

"DxOMark’s new Perceptual MPix measurements are based on acutance and human contrast sensitivity function (CSF) published in recently-released image quality standards from the International Standards Organization (ISO) and the International Imaging Industry Association (I3A). A member of the working groups involved in image quality, DxO Labs has been working diligently with giants in the digital imaging industry such as AMD, Nokia, Kodak, Nvidia, Fujifilm, HP, RIM, Intel, Microsoft, Google, and others."

an example that brings this into question for me is with the 400doii. according to dxo it has 29 p-mpix and the 300ii has 45 on the 5dsr.

According to lensrentals who test the lens on an optical bench the 400 is sharper. 1490 vs 1395

I know from experience that the 400 is super sharp but the contrast is a bit low. generally it needs some boosting in post but the resolution is there. Maybe that has something to do with the much lower rating dxo gives it?


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## 9VIII (Dec 2, 2015)

candc said:


> The thing I am most I am most interested in on the dxo site is the p-mpix measurement but I am not sure how exactly they measure it? This is what I can find on their website
> 
> "DxOMark’s new Perceptual MPix measurements are based on acutance and human contrast sensitivity function (CSF) published in recently-released image quality standards from the International Standards Organization (ISO) and the International Imaging Industry Association (I3A). A member of the working groups involved in image quality, DxO Labs has been working diligently with giants in the digital imaging industry such as AMD, Nokia, Kodak, Nvidia, Fujifilm, HP, RIM, Intel, Microsoft, Google, and others."
> 
> ...



As has been said many times, only DXO can say how they come up with their numbers.

http://www.lensrentals.com/blog/2015/01/more-canon-400m-do-ii-comparisons
The lensrentals article was for a single copy, not an average.
Comparing those numbers with TDP suggests the average would be somewhere lower than what Lensrentals had at the time.

http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=739&Sample=0&FLI=0&API=0&LensComp=962&CameraComp=453&SampleComp=0&FLIComp=0&APIComp=0


Another example, apparently the 300f2.8ISII has massive differences in resolution depending on orientation, but it's beyond me to see it on the test chart.
http://www.the-digital-picture.com/Reviews/MTF.aspx?Lens=739&FLI=0&API=0&LensComp=705&FLIComp=0&APIComp=0&CT=AVG


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## YellowJersey (Dec 2, 2015)

If you are going to go by dxo scores, you should probably look the individual scores for each category rather than the overall score. If dxo places a huge weight on in vignetting and you don't care about that vignetting, then the overall score is meaningless. 

I always take dxo scores with a grain of salt. Their weighting system seems weird to me, as vignetting seems to be the most important factor in determining the lens score. I also question some of their methods. Whether dxo is biased against Canon, I'm not sure. It kind of seems like it, but Canon's sensor tech has been lagging and you don't need dxo to tell you that. I knew something was up when I went shooting with a friend who had a D810 and just comparing the histogram with my 5D mkIII I could tell there was a big DR difference. The lens comparison does raise an eyebrow, though. 

But whether dxo is biased, I don't really care. DXO is but one tool and, imo, not the most important or valuable tool out there. I care more about what the reviewers say (Matt Granger, Jared Polin, Tony Northrup, The Camera Store, Dustin Abbott, Photorec Toby, and even those lovable goofs at Digital Rev) than what DXO says. And Canon's a big boy, it doesn't need anyone defending it from the big bad monsters at dxo. Dxo is not personally insulting you for using Canon. So take it on the cheek, recognise Canon's strengths, Canon's weaknesses, and move on.


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## StudentOfLight (Dec 2, 2015)

dilbert said:


> StudentOfLight said:
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> ...


Wide open apertures is a relative thing. Does a Sony/Canon/Nikon/Samsung/Pentax/Sigma 800mm f/1.2 exist?

Here is another example since you clearly didn't read my well laid out explanation earlier:
http://www.dxomark.com/Lenses/Compare/Side-by-side/Zeiss-Carl-Zeiss-Apo-Planar-T-Star-Otus-85mm-F14-ZF2-Nikon-on-Nikon-D700-versus-Canon-EF-400mm-F4-DO-IS-II-USM-on-Canon-EOS-5D__1384_441_1425_176

Note:


> DxOMark Score is a linear scale related to the largest print size that provides excellent quality. Doubling the size of the print requires doubling the DxOMark Score



With a score of 29 vs 17: According to the DXOmark score the D700 with Otus85 images (11MP of perfection) allows you to print 70% larger than what is possible with 5D with 400-DO-II images (12MP of perfection).

*Is the claim that Otus 85 (even with a slightly lower resolution sensor) produces 70% larger prints than 400 DO II a fair representation of the relative performance of the two lenses?*


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## 3kramd5 (Dec 2, 2015)

StudentOfLight said:


> *Is the claim that Otus 85 (even with a slightly lower resolution sensor) produces 70% larger prints than 400 DO II a fair representation of the relative performance of the two lenses?*



Of course, because you have to downsample (reducing those 12 million perfect pixels) to overcome the 3 stop noise disadvantage of the camera you're mounting the 400 to. Makes perfect sense!


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## candc (Dec 2, 2015)

It seems.that the "p-mpx" number that they give is a conglomerate score of sharpness at different apertures. That may be useful to know but if you want to know sharpness at a specific aperture (wide open comes to mind) then its best to look at the "accutance profile"

The accutance profile for the 400doii and 300ii are very similar wide open but the performance of the 400 drops off much more quickly as its.stopped down.


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## MrToes (Dec 2, 2015)

Some of them scores are quite surprising!?


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## StudentOfLight (Dec 2, 2015)

3kramd5 said:


> StudentOfLight said:
> 
> 
> > *Is the claim that Otus 85 (even with a slightly lower resolution sensor) produces 70% larger prints than 400 DO II a fair representation of the relative performance of the two lenses?*
> ...


Exactly, the 150 lux assumption!


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## rfdesigner (Dec 2, 2015)

The madness continues even when you compare canon to canon

http://www.dxomark.com/Lenses/Compare/Side-by-side/Canon-EF-100mm-F2-USM-on-Canon-EOS-5DS-R-versus-Canon-EF-85mm-F12L-USM-on-Canon-EOS-5DS-R-versus-Canon-EF-135mm-F2L-USM-on-Canon-EOS-5DS-R__798_1009_940_1009_630_1009

I'm very happy with my 100 f2.0 but is better than both the 135L and 85L? I don't think so!  

There's also so much they don't measure at all, so no one should take any of their ratings as worth more than the pixels they're written with, the underlying data has always seemed fairly genuine though.


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## JMZawodny (Dec 3, 2015)

bdunbar79 said:


> Boy that 300mm f/2.8L II IS lens sure seems like a truly perfect lens, huh? That is incredible.



Oh this is very bad news. After great effort, I had managed to rationalize not buying the 5DSR and to wait for the 5D4 (or 1DX2). Now this update comes along and it seems I must reconsider my logic. The 300mm f/2.8L II simply requires more pixels. I sort of subconsciously knew this already but have been in denial. I use my 300 a lot and have often wondered why I ran into pixels before I ran out of detail. My only course of action is likely to get 2 new bodies in 2016. Now to construct the argument that I will need to persuade my wife to go along with this.


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## PhotographyFirst (Dec 3, 2015)

rfdesigner said:


> The madness continues even when you compare canon to canon
> 
> http://www.dxomark.com/Lenses/Compare/Side-by-side/Canon-EF-100mm-F2-USM-on-Canon-EOS-5DS-R-versus-Canon-EF-85mm-F12L-USM-on-Canon-EOS-5DS-R-versus-Canon-EF-135mm-F2L-USM-on-Canon-EOS-5DS-R__798_1009_940_1009_630_1009
> 
> ...


Wait. WTF? 

The overall score makes absolutely no sense there. They must have messed up with their calculation or something. How can the 100 f2 be worse or equal in every category, yet be rated higher than the 135 f2? 

Man, I feel sort of sorry for any sap who buys lenses based on any DXO score. I guess lazy people get what they deserve sometimes, eh?  Still nothing beats just looking at full resolution sample photos of the lens you are interested in.


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## Bennymiata (Dec 3, 2015)

Another reason the same lens (Sigma etc) might have more vignetting on the Canon compared to a Nikon may be because Canons have a greater flange distance than Nikons have and certainly much more than FF mirrorless cameras.


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## rfdesigner (Dec 3, 2015)

Bennymiata said:


> Another reason the same lens (Sigma etc) might have more vignetting on the Canon compared to a Nikon may be because Canons have a greater flange distance than Nikons have and certainly much more than FF mirrorless cameras.



Correct, if the exit glass of the lens is smaller or more distant for the same size then more vignetting is likely.

Edit:

checking : https://en.wikipedia.org/wiki/Flange_focal_distance

Canon 44.0mm
Nikon 46.5mm

so nikon has more distance.. I don't know about the exit glass diameter though.
/Edit



PhotographyFirst said:


> rfdesigner said:
> 
> 
> > The madness continues even when you compare canon to canon
> ...



At first I thought price might have an influence.. the 100 f2.0 does score well on bang for buck.. but then the 50f1.8STM ought to be best of all lenses, and it isn't.

So DxO scores are simply numbers plucked out of the ether.


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## weixing (Dec 3, 2015)

Hi,


Bennymiata said:


> Another reason the same lens (Sigma etc) might have more vignetting on the Canon compared to a Nikon may be because Canons have a greater flange distance than Nikons have and certainly much more than FF mirrorless cameras.


 Canon had shorter flange focal distance than Nikon... you can mount Nikon lens on Canon body with an adapter and will work, but not the other way round.

Have a nice day.


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## PhotographyFirst (Dec 3, 2015)

For a Sigma or other 3rd party lens, the flange distance doesn't make any difference. The optical formula still has the elements in the same positions and sizes between camera brands. It just mounts at a different position. 

The vignetting variation is most likely due to the sensors themselves. Which is interesting, because I never thought there was much difference in that regard.


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## Stu_bert (Dec 4, 2015)

PhotographyFirst said:


> For a Sigma or other 3rd party lens, the flange distance doesn't make any difference. The optical formula still has the elements in the same positions and sizes between camera brands. It just mounts at a different position.
> 
> The vignetting variation is most likely due to the sensors themselves. Which is interesting, because I never thought there was much difference in that regard.



Hmm. But surely it does. In the same way the different micro lenses might affect it, in terms of how they alter the path of the light, then the distance from the sensor will affect where the light falls?

Would comparing vignette on a 5d lens, with somewhat different sensor tech to a 1dx with the same lens, show how much the sensor does contribute?


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## StudentOfLight (Dec 4, 2015)

Stu_bert said:


> PhotographyFirst said:
> 
> 
> > For a Sigma or other 3rd party lens, the flange distance doesn't make any difference. The optical formula still has the elements in the same positions and sizes between camera brands. It just mounts at a different position.
> ...


Read this technical piece by Brandon from Lensrentals:
http://www.canonrumors.com/forum/index.php?topic=26782.msg529529#msg529529


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