Interesting ... - Printable Version

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Interesting ... - Klaus - 11-12-2016

I'm currently revisiting the 11-24L to get the 21mp MTFs.

Quite a change ... ;-)

Interesting ... - Klaus - 11-12-2016

Also funny - the 11-24mm has a maximum CA of 8px in the extreme corner (on 51mp).

One of the reasons why the resolution tanked so much at 11mm.

Interesting ... - Brightcolours - 11-12-2016

The software you use is nit very reliable to measure CA anyway, as we have noticed in other reviews (sometimes the samples do not tell the same story at all as the software's number). Not your fault, of course. But it is then a bit difficult to rely on the CA test numbers to compare lenses.


And I still am on the position that the sharpening done in the MTF workflow is to blame for skewed lower results for corners. It would be interesting to see scores with no sharpening applied at all in the MFT measuring workflow. My prediction is that the difference between center and corner sharpness is very much reduced.

Interesting ... - Klaus - 11-12-2016

What is the real world use case for non-sharpened results ? On the 5Ds R (and A7R II, Fuji X-T1) the sharpening is already minimal (due to the lack of an AA filter).


Also - those 8px wide CAs are clearly visible.

Interesting ... - Brightcolours - 11-12-2016

The sharpening exaggerates the sharp results (center) and will not touch results below a certain threshold (corners). Especially the minimal sharpening will have this effect... Stronger sharpening will have a lower threshold. 


The sharpening just makes corner results look weaker in comparison to center, that they really are. Of course, not talking about the CA that also lowers resolution and contrast.


I do not have the camera(s) and equipment to test the difference, so I can't show the difference.

Interesting ... - Klaus - 11-12-2016

Sure, you are right but again - what is the point of using unsharpened images ? Nobody uses unsharpened images in the real life.

In essence we are using the default output of a camera (not really but sort of) - just like the rest of the photographic world.

Numerically this is emphasizing sharper spots ... so ? It's just a increased spread - no more, no less.


We've been through all this numerous times.

Interesting ... - Klaus - 11-12-2016

Ah, I now understand what you mean here. Yes, the 21mp are relatively sharper on pixel level thus more receptive to sharpening.

Interesting ... - davidmanze - 11-13-2016

 My 2 cents!

                   It's not just about sharpness and sharpening, but also about detail and resolution. A blurred edge in an image of 50 Mps could cover 6-8 pixels, on 21 Mps it might only cover 3 pixels, on 6 Mps it maybe only one pixel, or with positional luck, maybe even none at all, giving the impression of perfect sharpness, in-spite of low resolution and poor detail,  hence the sharp images we were getting years ago from 4Mps sensors. (not breaking news,  however, it is a contributing factor nonetheless). 


  The bottom line is, that, after being tested on the 5DSR, a lot of perfectly good lenses will find themselves,  standing about trembling shamefully.......... with their pants around their ankles!

Interesting ... - Klaus - 11-13-2016

Didn't we say that already ;-)


However, at the end of the day it doesn't matter - if the blur is higher - thus less receptive to sharpening - the chart will only express that the lens is not up to the task of exploiting the sensor potential ... which is the idea behind all this in the first place. :-)

Interesting ... - davidmanze - 11-13-2016

"Didn't we say that already?"


Where?    In another life? ..... I've looked high and low and I see nothing whatsoever about lenses having their pants around their ankles!



BTW.  Klaus I see your letter representatives for emoticons but I never see the faces!  :o