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

Started Apr 10, 2013 | Discussions thread
qianp2k
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Re: not sharpness
In reply to John Sheehy, Apr 11, 2013

John Sheehy wrote:

qianp2k wrote:

John Sheehy wrote:

Mako2011 wrote:

You seem to be mixing terms and describing sharpness but calling it resolution.  Resolution only describes how much detail a camera/lens is capable of capturing — and not necessarily the quality of the detail that is captured. The problem, in these types of discussions, is that folks keep mixing related terms an using them to describe inaccurately a concept

Did you actually read my post?  It seems very unlikely, given your response.

He doesn't care the quality of pixels (or detail) that's why I keep using 41mp Nokia 808 to remind him  For him, 41mp is 41mp regardless of the huge loss thru imperfect lens and loss in crop enlargement, regardless if his eyes actually can resolve details or not.

40MP pixels is and always is, 40MP.  "MPs" is the maximum number of sampling elements, regardless of potential contrast.  Sampling should, ideally, be soft, at the pixel level.  Not by having too strong an AA filter, or by having a soft lens, but by having enough pixels that pixel softness is the result.  You can not record an image without spatial distortion, if you have high contrast in the RAW capture at the pixel level.  It is impossible.  A 40MP sensor will always be able to record alternating darker and lighter lines on alternating lines of pixels, at some level of contrast, unless the AA filter or diffraction is ridiculous, in which case the noise will be much stronger than the signal.

Sure 41mp in Nokia 808 is only 41mp on paper. But there is simply no such perfect lens existed that can fully resolve that 41mp and compensate huge crop penalty (as those pixels are enlarged many times bigger to project on the same size output). I think if DXOMark ever tested it, its P-MPIx will be only 4mp at the best. I have seen 808 100% cropped that I cannot see much details when you look closely that are not washed out.

In the case of the Nokia, it doesn't seem that the system is getting much, if any, undersampling, which means that the 40MP is a good thing.  It will downsample to a much better 12MP image than a 12MP sensor, and it will be much better printed large at 40MP than it would be from a 12MP sensor.  The only downside to having 40MP is speed and storage.

I have seen DPR Connect tested several cell phone cameras including 808. I don't see 808 takes better or even much more detailed photos than iPhone 5 or Samsung SIII. The fact is that Nokia 808 or any cell phone cameras in today markets never be able to generate those photos with that levels of fine details as shown in my 12.8mp 5D with 24-105L, 17-40L and 50/1.4 at a given size said 30x20" print or 3000-pixel wide JPEG.  Otherwise please post any photos from 808 and let us see.

He denies crop penalty in other posts in other threads before (but all these concepts are related to each other)  that's why I also keep using another vivid case that nobody should buy 600mm lens that all PJs should use 300mm on 2.0x crop or even better 30mm on 20x crop, LOL.  I know he will again suggest me off-topic  But if he cannot address these two vivid cases (Nokia 808 and 600mm lens), he doesn't understand resolution or perceptual sharpness (resolution or fine details as I prefer to call)

We haven't seen the Nokia's sensor with a lens that isn't designed to sit very close to the sensor, which is probably a major reason why the 40MP images aren't as sharp at the pixel level as many other cameras.  Regardless, the 40MP still gets 40 million samples; none of them redundant.

The key factor is that no such lens ever existed or ever can be designed and manufactured as long as we still stay in glass lens that can fully resolve 41mp from the sensor. Even there is such perfect zero-lost lens ever existed, 41mp from Nokia 808 still will not be real 41mp after deduction from huge crop enlargement. It would resolve far less than 36mp D800, 22mp 5D3 or even will not resolve more than 12.8mp 5Dc.  Don’t forget crop penalty.

That's why I said there is simply no such sensor resolution as it has to go thru lens and has to face crop enlargement and crop penalty (FF also has crop penalty but just less and MF has much lesser).

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