1. Here you are my samples:
indoor and film
Pentax 645D test DFA 90/2,8 indoor - managger -
outdoor
Pentax 645D test DFA 90/2,8 outdoor - managger -
You can click on "original size" and download every photo.
If you want to download all photos at once (in original size) - here you are two archives:
Indoor.7z Outdoor.7z Originally posted by 672 Ristretto indicated that his copy had corner darkness at 2.8 on his 645D.
2. So, I have found his direct words about this subject in the neighbor thread:
https://www.pentaxforums.com/forums/pentax-medium-format-645-6x7-645d/214034-...ml#post2269456
"
Real macros I didn’t yet test out very deeply. What I noticed is a vignetting on aperture 2.8 for about 0.5 – 1 stop in the corners."
He did not speak about "dark corners" - he speak about "vignetting" !
As for me, "dark corners" means that the lens is not a "full-frame" on 56x41,5mm,
and "vignetting" means little worsening in the corners at the open aperture on 44x33mm, nothing more.
3. I can add some information to this question.
Have a look at the standart focus-chart:
DI_04313.jpg - Pentax 645D test DFA 90/2,8 indoor - managger -
Click on original photo: 7264 x 5440 (14,4 Mb)
Pay attention to the corners - the text "
3 1/8" is slightly worse than the text "
2 3/4".
It's absolutely normal I think, because every lens performs it's best in the center,
and of course starts to decrease resolution sooner or later, especially at open aperture.
Originally posted by Ristretto I think it's obvious... If it would be the lenshood, then it would appears on all apertures, not only at 2.8.
In fact, for me that vignetting isn't really a problem. When I shoot on 2.8 it's because I like to point out the principle thing in the picture. And this rarely is found on the corners... In addition vignetting is one of the problems that can easily be corrected by any RAW-Converter.
Thank you, my observations are the same, and thoughts are the same too