« on: September 06, 2014, 06:57:11 PM »
I said I trusted DXO lens scores to a degree and other reviewers reflected my experience with the lenses tested. IE: Abbotts 135mm APO tests.Your absolutely correct and that's what I've been saying. To get near the 50mp resolution, you would now need supreme lenses to see a major difference. 36--->50mp would be a small jump with most lenses(negligible)and like you mentioned, huge if with an Otus.The page supports it. You will never get 50mp or even close to it with most lenses. The jump from 36mp to 50mp will be slight with most lenses and stark with supreme lenses. Even with aps cams, the difference is the same, indistinguishable with most glass and stark with supreme glass. That's why cropping FF 22mp vs aps 18mp the results are nearly identical. On paper they shouldn't be, but on the other thread, negligible.
The point I was trying to make before was that you can't get 50mp with any existing lens, and probably wouldn't with any lens created within the next decade. The same goes for 36mp, 24mp, 18mp. You cannot actually resolve those resolutions with ANY lens, even the best of the best of the best. Because output resolution has an asymptotic relationship with the least resolving component of the system. To even get close to 50mp, you would probably need to be shooting a lens like the Otus at f/1.4 (assuming it's diffraction limited at that aperture...if not, then you would need a lens even better than the Otus).
Assuming you don't have a crappy lens, then you can realize improvements by moving to a higher resolution sensor. Every time you do, the nyquist limit drops. That allows more information to be resolved usefully. It might be resolved at lower contrast, but until your down near the Rayleigh limit, you can still do stuff with lower contrast detail (it's more work to enhance it, but it can be done.) If you jump from 18mp to 50mp, even with just an "ok" lens, your going to see a huge difference. The frequency of detail that might have been resolved crisply at 18mp will now probably look a little soft...however, your going to be resolving a level of detail the 18mp couldn't even see at all. The same would go for the difference between 36mp and 50mp...although the amount of smaller details you resolve wouldn't be as significant, and would require more work to enhance.
For any given lens, going from 24mp to 36mp, then to 50mp, WILL realize an improvement. The improvement might start out at around 18% for the jump from 24-36mp, then drop to 11-12% for the jump from 36-50mp. It might be a mere 5% in a jump from 50mp to 70mp. Beyond that, your probably within the margin of error...however, then your in the realm of oversampling. That has a whole 'nother set of benefits.
Back to my original statement, forget about getting the most out of those 50mp with the current selection of native lenses in the A7 mount. Added on top with the small pixel size, extra camera shake.
Ah, ok. I guess I misunderstood something along the line, when you said you believed DXO when they stated the Zeiss 135 could actually get 36mp out of the D800. Good to know we agree.
I don't know much about native lenses for the A7 mount...however, I would really be interested in seeing how some of Canon's newer lenses work with that sensor when adapted to the A7 mount. I bet the 24-70/2.8 II is phenomenal.