LarsHP wrote:
You are either misreading or misunderstanding.
As you can see from the link I provided above, the vignetting test with the Summicron and Ultron were done on the same camera, my Z6UT. That means apples to apples and proves my point, yes.
(I have also done some optical vignetting tests that support this point, but haven't posted those.)
My point you are quoting here refers to why Bastians test shows less vignetting than my test WITH THE SAME LENS, namely the Ultron II. So, the difference in illumination between the M10 and Z6UT is sensor related (caused by the micro lenses). That explains why we can't compare his and my vignetting images.
EDIT: In the YouTube review Benj Haisch did, it is also quite evident that the bokeh balls (in the bushes) from the Ultron II are clearly oval-shaped already in the mid-frame which isn't the case with his Summicron Asph II. This is consistent with what I am saying.
Steve Spencer wrote: LarsHP wrote:
I should add that vignetting in my Kolari Vision Ultra Thin modified Nikon Z6 was stronger than the Leica M 240 that I tested my Summicron on. This means the vignetting (from any lens with quite short exit pupil) will be stronger in my test than yours, since you used your M10, I expect.
BastianK wrote: Steve Spencer wrote:
I am posting below the vignetting curves that Bastian included in his review of the Voigtlander 28 f/2 II and the official vignetting curves from the Leica data sheet for the 28 summicron Asph.
Those graphs are not directly comparable.
Part of the reason for that is that all I can measure is the whole "system" of sensor, in camera processing, lens, post processing/raw development.
Whereas - I am guessing - Leica gives data for the lens only. And even if not, their process chain is most likely different from mine.
The Leica's corner illumination at f/2.0 is roughly 21% acc. to that graph, which would translate to -2.25 EV.
That does sound surprisingly low to me, at least on digital.
On film it might very well be true though, due to the absence of pixel vignetting.
And that means of course that your test was an apples to oranges test and that has to be considered when comparing the two lenses. And, in my view, given that the summicron in your test had a clear advantage and the difference in vignetting is small at best your own tests provide pretty strong refutation of your own position that the summicron is night and day better than the Voigtlander.
Yes, I did misunderstand what you were saying, but that is my fault. By I don't think you tests "prove" anything or come close to proving it. They show with that camera (Z6 UT) slightly less vignetting for the summicron than the Voigtlander which in no way support your rather large claim that the Voigtlander is not at all useful at f/2 over f/2.4 while the summicron is. That is just way too big of claim to be supported by one test that shows minimal differences, IMO, rom a camera that is not even designed to used the lenses.
Sep 20, 2022 at 12:06 PM
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