DPReview: Canon EOS R vs Nikon Z 6 vs Sony a7 III, which is best?

Don Haines

posting cat pictures on the internet since 1986
Jun 4, 2012
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It can in fact become a worse lens on crop! The smaller sensor has more lines pairs per mm and so you have to look at the higher level MTF values of the lens with the crop to get the equivalent for the FF. For example, the 30 lp/mm MTF for the crop is equivalent to the 20 lp/mm of the FF, and the 48 lp/mm MTF for the crop is the equivalent of the 30 lp/mm of the FF for the overall resolution of the sensor. So, a lens that has a very good value of the 10 lp/mm and OK 30 lp/mm but deteriorates rapidly with increasing lp/mm will be OK for FF but weak on crop. The high quality lenses like the 300mm f/2.8, 100-400mm II perform well on crop. My old 100-400mm Mk 1, a poor copy, was quite good on FF but rubbish on crop.
No, the quality of the lens does not change. The optics are the same.... in fact, on a crop body you are only using the sweet spot in the middle of the lens so the overall performance should be better.

What does change is that crop sensors are (usually) higher pixel density, and as such need a higher resolving lens to achieve the same apparent sharpness as a FF body, so yes, the image will appear fuzzier than a similar image on a FF camera taken with a lens of similar sharpness..

That said, DXO does not rate the lens in line-pairs, they rate it in megapixels of sharpness....

And here is where it gets real silly fast. Take the 7D2 and the 5DS R. Same lens on both cameras. The pixels on the camera are the same size, yet the poorly named "sharpness" metric plummets. In reality, this so called metric is not as much about lens performance as it is about the number of pixels on the sensor.

We end up with a metric that can not even be used to properly compare the same lens across two cameras in the same brand! How could it possibly be used to compare between two different brands? Or even worse, two different lenses on two different brands!

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Likes: Refurb7
Aug 16, 2012
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I am not arguing about the validity of the DxOmark scores, I am pointing out that crop and FF sensors have different MTF frequency requirements for their lenses. It is not the point whether or not DxO is rating the lens in lp/mm or mpx. The heart of the matter is that a lens can perform differently on a crop sensor versus a FF depending on the frequency dependence of its MTFs. A small sensor requires a high resolution lens, and is more demanding than a large sensor of the same mpx. As an aside, a high density sensor also requires a high resolution lens.
 

Don Haines

posting cat pictures on the internet since 1986
Jun 4, 2012
7,521
633
Canada
I am not arguing about the validity of the DxOmark scores, I am pointing out that crop and FF sensors have different MTF frequency requirements for their lenses. It is not the point whether or not DxO is rating the lens in lp/mm or mpx. The heart of the matter is that a lens can perform differently on a crop sensor versus a FF depending on the frequency dependence of its MTFs. A small sensor requires a high resolution lens, and is more demanding than a large sensor of the same mpx. As an aside, a high density sensor also requires a high resolution lens.
100% agreement! I think we are saying the same thing, only from a different direction.
 
Aug 16, 2012
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I do agree that the DxO scores have so much real garbage in them. The overall score for a zoom lens, for example is based on its optimal focal length, which will be different for different brands of lenses, rather than on say the longest or shortest. I also reported some yeaers ago that they clearly haven't measured the scores on all the bodies in their comparison charts but have clearly done just a few and scaled them for other bodies.
 

scyrene

EOS 6D MK II
Dec 4, 2013
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Perhaps I've been filtering differently, but the past year I've read here much more of, "If you want that feature, go buy brand X." Or, "You mean you can't take good pictures with a 5D III or 5D IV?" And so forth. Maybe it's troll-fighting fatigue?
Maybe. Tbh I haven't been using the forums as much since they changed the format, I don't find it as easy to follow what's going on :confused:
 
Mar 26, 2014
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Normally I would agree with you, but in this case they are talking about FF cameras, and just that alone excludes about 95 percent of the users.
The reference group I was referring to was FF camera owners, like me. My bet is 95% of those wouldn't buy a 50mm f/1.2 or a 28-70mm f/2, at least not at those prices.
 
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flip314

I'm New Here
Sep 26, 2018
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The reference group I was referring to was FF camera owners, like me. My bet is 95% of those wouldn't buy a 50mm f/1.2 or a 28-70mm f/2, at least not at those prices.
I tend to agree.

The 28-70 f2 is mostly a status symbol, and I say that as someone who really wants one... I'm sure when the RF 24-70 f2.8 comes out it will be a much more practical lens (and is probably what I'll actually end up with), and it wouldn't make a lot of sense to own both. Even then, the 24-105 f4 is probably already good enough for what most users want (sales volume wise).

The 50 1.2 also sounds amazing, but even for people who venture outside of zoom lenses probably more lens than they need. I expect the eventual 50mm 1.4 or 1.8s will be much more popular.
 

Don Haines

posting cat pictures on the internet since 1986
Jun 4, 2012
7,521
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Canada
The reference group I was referring to was FF camera owners, like me. My bet is 95% of those wouldn't buy a 50mm f/1.2 or a 28-70mm f/2, at least not at those prices.
Personally, I am the same. When I eventually get some model of the R mount, portability will be high on my requirements, with my ideal lens being an R mount version of the 16-35 F4, and using my existing F4 lenses through an adapter. The 28-70 F2 may be a fine lens, but I want something lighter to carry around.
 
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privatebydesign

Would you take advice from a cartoons stuffed toy?
Jan 29, 2011
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And I'm not looking at it, at least until it has the lenses I want.
Which proves my point, when/if you do buy one you'll use the camera with the lenses so however you want to cut it the body can't be tested in isolation, that is, it is disingenuous to 'test' one against the other without the lenses being an important part of the conclusion. In my world the reason for the body is to take lenses to create pictures, I can take more compelling and unique images with the Canon than the Sony or Nikon, but that counts for nothing.

Don't get me wrong, I don't care what people do or don't do, I just think this reviewing process has completely moved away from the raison d'etre of the tool in hand and become a sales shark feeding frenzy where everybody is vying for affiliate links.
 

YuengLinger

EOS 6D MK II
Dec 20, 2012
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Which proves my point, when/if you do buy one you'll use the camera with the lenses so however you want to cut it the body can't be tested in isolation, that is, it is disingenuous to 'test' one against the other without the lenses being an important part of the conclusion. In my world the reason for the body is to take lenses to create pictures, I can take more compelling and unique images with the Canon than the Sony or Nikon, but that counts for nothing.

Don't get me wrong, I don't care what people do or don't do, I just think this reviewing process has completely moved away from the raison d'etre of the tool in hand and become a sales shark feeding frenzy where everybody is vying for affiliate links.
Nobody you feel is go-to, reliable, objective anymore? Maybe I'm misreading you here...
 
Mar 26, 2014
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Which proves my point, when/if you do buy one you'll use the camera with the lenses so however you want to cut it the body can't be tested in isolation, that is, it is disingenuous to 'test' one against the other without the lenses being an important part of the conclusion. In my world the reason for the body is to take lenses to create pictures, I can take more compelling and unique images with the Canon than the Sony or Nikon, but that counts for nothing.
Yes, with the lenses. No, not with the RF 50mm f/1.2 or RF 28-70mm f/2, unless I happen to win the lottery.
 
Feb 26, 2017
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I tend to agree.

The 28-70 f2 is mostly a status symbol, and I say that as someone who really wants one... I'm sure when the RF 24-70 f2.8 comes out it will be a much more practical lens (and is probably what I'll actually end up with), and it wouldn't make a lot of sense to own both. Even then, the 24-105 f4 is probably already good enough for what most users want (sales volume wise).

The 50 1.2 also sounds amazing, but even for people who venture outside of zoom lenses probably more lens than they need. I expect the eventual 50mm 1.4 or 1.8s will be much more popular.
28-70 is a bread and butter lens for event shooters and having a whole one full stop faster lens attached to you camera frequently means keeping ISO of your shots in 3200 territory instead of 6400. that is a massive difference in my books. that along sparked my interest in the promising albeit still largely incomplete R system.
 
Likes: Del Paso
Aug 11, 2016
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DPR has decided that spec sheets, feature parity and performance are the metrics that mainly define which camera reviews well. Members that don't agree with DPR believe they should have considered other comparison metrics "they" feel are important to them like Canon's EF back catalog, pro support, market share, subjective color science and perceived ergonomics. If DPR was so against the grain in choosing the wrong comparison metrics, so technically inept in their operation of various cameras in their reviews or displayed a specific anti-bias towards particular brands, their readership and longevity would have proven otherwise. Clearly they understand their own target audience who consumes these reviews and have met that audience accordingly.

I'm not sure this is any different than me thinking that Canon should include IBIS or FF crop in video. It's important to "just" me...

Anyone can of course make their own decisions regardless of any review, but if you come out and criticize a review site of this scale, make sure to provide a resume and social presence consisting of plenty of specific technical reviews and images that can illustrate your own credibility in the areas being criticized. Otherwise, they are simply opinions.
 

privatebydesign

Would you take advice from a cartoons stuffed toy?
Jan 29, 2011
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Nobody you feel is go-to, reliable, objective anymore? Maybe I'm misreading you here...
Ha, I rarely put any weight behind a review because I never knew of a reviewer that wanted what I want...

Obviously there are good reviewers out there but even the most even handed end up showing patterns that I never managed to replicate, Dustin with his Tamrons, Brian with his anything with a Canon badge on it, etc etc. I watch them for trends and entertainment, I don't give a damn what they actually say and whatever that is plays no part in my purchasing decisions.

Actually no, I thought of one, the only reviewer I really trust is Kieth Cooper over at Northlight Images.
 
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privatebydesign

Would you take advice from a cartoons stuffed toy?
Jan 29, 2011
7,223
203
118
DPR has decided that spec sheets, feature parity and performance are the metrics that mainly define which camera reviews well. Members that don't agree with DPR believe they should have considered other comparison metrics "they" feel are important to them like Canon's EF back catalog, pro support, market share, subjective color science and perceived ergonomics. If DPR was so against the grain in choosing the wrong comparison metrics, so technically inept in their operation of various cameras in their reviews or displayed a specific anti-bias towards particular brands, their readership and longevity would have proven otherwise. Clearly they understand their own target audience who consumes these reviews and have met that audience accordingly.

I'm not sure this is any different than me thinking that Canon should include IBIS or FF crop in video. It's important to "just" me...

Anyone can of course make their own decisions regardless of any review, but if you come out and criticize a review site of this scale, make sure to provide a resume and social presence consisting of plenty of specific technical reviews and images that can illustrate your own credibility in the areas being criticized. Otherwise, they are simply opinions.
That's a ridiculous premise, they are popular so what they count is important. American Idol gets more viewers than the news....
 
Aug 16, 2012
4,430
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Ha, I rarely put any weight behind a review because I never knew of a reviewer that wanted what I want...

Obviously there are good reviewers out there but even the most even handed end up showing patterns that I never managed to replicate, Dustin with his Tamrons, Brian with his anything with a Canon badge on it, etc etc. I watch them for trends and entertainment, I don't give a damn what they actually say and whatever that is plays no part in my purchasing decisions.

Actually no, I thought of one, the only reviewer I really trust is Kieth Cooper over at Northlight Images.
All of the sites have their fans, but I am as sceptical as you and read all the reviews possible to search for some common truths.There are some sites that are pretty objective: lensrentals of course is scrupously so and extremely rigorous but limited; lenstip and opticallimits are unbiased and concentrate on metrics; ephotozine similarly so; TDP does give comprehensive and accurate accounts of Canon goods and is very useful but I don't like his lens comparison charts; and useful stuff can be gleaned from many others. There is a good living to be made by having a fan base on youtube and elsewhere.
 
Aug 11, 2016
139
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That's a ridiculous premise, they are popular so what they count is important. American Idol gets more viewers than the news....
But why are they popular in the first place?

And last time I checked, American idol doesn't report on the news. If you told me American idol dictates what is happening in the news, yes, I would consider that a ridiculous premise based on popularity.
 
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