Return of Interesting article on DxO about 5D III and D800...

Started Apr 10, 2013 | Discussions thread
schmegg
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Re: Return of Interesting article on DxO about 5D III and D800...
In reply to qianp2k, Apr 14, 2013

qianp2k wrote:

schmegg wrote:

qianp2k wrote:

The result is clear as we have seen from tons of real world photos from respective cameras.

In terms of resolution, I've not seen that.

Which resolution, MTF 50 or 30 or below 20?  I doubt your eyes can see MTF 20% or below in real world photos where 60D/7D suffers higher grains/noises (that is also measured on SNR ratio that even 8-yr-old 5D is still noticeable higher cross entire range of ISO 100-3200).  MTF 50 or at least MTF 30 resolution ultimately matters to normal human eyes

Really? Why's that Peter?

And you've been unable to show this yourself with your 5D and 60D.

Actually shown well in my test samples between 5D and 60D even with one of the best lenses I used in test, 24-70L II.

No - you didn't. The overwhelming consensus is that the 60D out-resolved the 5D in your examples - even after you added false detail to it's recorded image by upscaling it.

I gave 60D an advantage by upsampling 5D file to the same size of 60D for easier comparison (without a wrong perception that bigger size has more resolution).

As above - and this was pointed out to you by a few others in that thread too - upscaling adds false detail to the image. It's simply not a valid compariosn.

Despite this though - the 60D still out-resolved the 5D.

Please not to repeat words over and over again as we have debated enough in that thread.  The ones shown 60D with 24-70L II has very slightly higher resolution on the dollar bill (in very small center area) exactly shown in that very close distance (macro mode) under perfect light condition, grainless/noiseless, so around MTF 20% I guess.

Yes - higher resolution from the crop.

But I have not shown edges/corners yet where it would show with even 24-70L II, 5D haa higher resolution.  So should we consider AVERAGE frame resolution rather very small center resolution.  With inferior lenses and in real world photos, then 5D leads larger while 7D will be hammered more in higher noises/grains.

http://www.dpreview.com/forums/thread/3447852?page=7

http://www.dpreview.com/forums/thread/3447852

5D + 24-70L II upsampling to the same size of 60D

60D + 24070L II

Though I can easily show an 18MP crop image will resolve more of the detail projected onto it than a 22MP FF.

LOL.  Please put a disclaimer next time when you show your "currency bill" shots side by side with 7D and 5D3 that you shoot from the same distance with the same focus length, then you crop out 5D3 photo to match to 7D AOV in very small center area (currency bill).  In such senario, then I have no dispute as that kind of test is meaningless.

Nope - why do I have to keep repeating this for you?

The only way to determine which of two sensors is capable of resolving more detail is to present each with exactly the same projected detail and then see which resultant image has resolved more of it!

That's precisely what my test does. Not meaningless at all - it's in fact the only way to determine which sensor can resolve more.

All creditable lab tests are tested under the same AOV for the same scene.  With different AOV from same distance/same length  you ended with two different photos, two different scenes.

And, when you did this in your 5D/60D test, it still showed the 60D resolving slightly more.

If you believe your 18mp 7D resolves more than your 22mp 5D3, you should use 7D in your landscape, studio and portraiture photography.  That's only your choice.  I know I will pickup my 5D cameras over my 60D anytime (except from operation consideration when I want to carry smaller/lighter 60D) in those areas of photography 

Fine.

Why do you think this is? Could it possibly be that you don't know how to read those lines properly I wonder? For instance, did you realise that both those graphs show that the crop resolves more than the FF but with less acutance? I guess not.

Please understand these articles to understand MTF resolution.  BTW, your 22mp 5D3 has higher MTF resolution than 18mp 7D in any MTF percentage from 1-100% as long as frame the scene in the same AOV.

No dispute there.

Once again it goes to show the folly of using lens tests to draw conclusions regarding the resolving capabilities of different sensors. All those MTF curves will tell you, when it comes to comparing different sensors, is that lower resolving sensors will give you sharper images from lenses of lesser quality than higher resolving sensors - and that's what you can see with the 85/1.8 - and why the MTF lines are much closer with the 100/2.8.

The tests are measuring acutance and it stands to reason that larger pixels will give increasingly sharper images at pixel level than smaller ones as the lens quality drops. It actually says very little about the relative resolving capabilities of the sensor and a whole lot more about the quality of the lens (surprise, surprise! Who'd have thought that a lens test would be measuring the performance of a lens! LOL!)

Please read and understand.  Both acutance and MTF resolution are related in what human eyes can resolve, the term Perceptual Sharpness DXOMark uses.

And please try to understand that acutance, sharpness and resolution are different things! (why is this so hard?)

BTW - I can now see why DxO don't publish them any more! This is a good example of why they tried to come up with something a little easier for people to understand!

I believe DXOMark P-MPix makes senses to help most people (especially beginners) to understand easier.  Most (think about members in DPR are still minority among all photographers in the world) don't understand MTF data well no mention which MTF resolution, 50, 30, 20, 10?  In real world photos MTF 50 or at least MTF 30 ultimately matter to human eyes.  Under overwhelming most real world scenarios your eyes just cannot see MTF 20% or below or at least not easily.

I think that depends a lot on what you are doing with your images. Remember that these MTF figures are for 'unprocessed' images. That's not a good guide as to how the final image may be presented. It doesn't matter because these are LENS TESTS! Sheesh!

Remember, if you will, that acutance can be adjusted during post processing. So, as long as the detail has been resolved, there are ways to recover it. However, if the detail has not been resolved in the first place, then all you can do is 'invent' false detail (like you did in your 5D/60D test). And, in this very real respect, a higher resolution image with lower acutance is more useful than a lower resolution image with high acutance.

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