[Will Chao]

Just curious if the 85L will perform better on the 5DS downsampled to 22mp compared to native 5D3?

 

Wide open of course

 

Has anybody done these tests? Hopefully Photozone will review this lens on 50mp as well soon

 

I'm looking at every possible way to improve the image quality of my 85L

[JJ_SO]

I'm curious: What kind of magic do you expect? If a lens is not up to your expectations at half the resolution, all flaws will first double (roughly) and with downsampling come to the same result as you already have.

 

Also, the motivation for retesting on 50 MP is kind of tricky. A couple of lenses will look worse, so you won't buy the lens or if you alrerady have it, won't buy the camera.

 

When D800 came out, there was a debate wether PZ should or should not update to this HR camera. Reason not to do was "only 50% plus of resolution doesn't mean enough to justify the costs - and the former test wouldn't be comparable", if I recall correctly.

 

Do you know the site lenscore.org? They do test on a 200 MP sensor with some kind of adaptor. Good thing is, this sensor is the same for all lenses (Canon, Nikon, Sony, Sigma, etc.) and the bad thing is, some people find they are not transparent in their test scenario and all those numbers are bullshit. Same as with DxO.

 

I think even if the numbers are of strange origin, the origin is always the same and then comparable.

[Brightcolours]

Just curious if the 85L will perform better on the 5DS downsampled to 22mp compared to native 5D3?

 

Wide open of course

 

Has anybody done these tests? Hopefully Photozone will review this lens on 50mp as well soon

 

I'm looking at every possible way to improve the image quality of my 85L

a look at the current 22mp MTF:



It shows us that the lens is pretty sharp wide open, in the center. This will mean that: yes, you will get more resolution in the 50mp file than in the 22mp file. The borders, probably not so much more resolution. But those generally are not that important wide open, since the DOF is small.

 

You of course will not get better IQ from the lens. However, you will get better IQ from the sensor, noise wise (The 5Ds has less intrusive pattern noise), and will be able to make bigger prints and stand up close and not see the individual pixels (but one normally doesn't stand up close to bigger prints).  Why one would want to downsample to 22mp, I am not clear about. That seems a time-wasting exercise?

[popo]

I presume the downsampling is to allow a comparison at the same pixel scale factor. I would expect some gain since it would partially negate the colour resolution loss in bayer pattern sensors.

[Will Chao]

Thanks for your replies people!!

 

JoJu - I'm not expecting much magic, I am in fact quite happy with the 85L performance on 5D3 but any improvement is welcome right? I am aware that this lens will possibly look worse at the pixel level on 5DS but I'm not really concerned about the pixel level, I just need to know whether it will have better IQ than the 5D3 when downsampled to the same 22mp

 

Brightcolours - Obviously, being able to use 50mp to do large prints is handy, but even when printing small-medium sizes such as 12 x 8 which only uses so much megapixels, it would be reassuring to know that 5Ds would have better IQ with the 85L than the equivalent 5D3

 

Popo - That's a very good point! I guess I will go borrow/rent a 5Ds and do some comparisons myself as I am pretty much sold on the 5Ds now. Even if I don't use 50mp regularly it still helps to know that my overall image quality (regardless of lens) will improve

[JJ_SO]

I don't see the benefit of taking pictures at 50 MP and downsample it to an amount your 5D3 already has. You lose all the resolution you paid pretty big bucks for and you gain no better noise than 5D3 already has, I assume (but I may be wrong assuming). Anyway, it's a good idea for sure to try it yourself.

[Scythels]

You will get moderately better res after downsampling than you will shot at native resolution, but the gains will not be huge.  15% or so.  You can compare the pure, measured MTF against the 85mm f/1.8G here instead of using LensScore: http://www.the-digital-picture.com/Revie...p=0&CT=AVG


Eventually there will be a full aperture series for both lenses, but today is not that day.