I've received another copy of 24-105 F4. It is much better than the first one, but there is something wrong with it. I've tested all focal lenghts on F4 and F8. On every single shot on all focal lenghts there is always the same situation:
Center is much sharper on F4 than on F8, corners are sharper on F8.
My procedure test looks like this:
a) tripod
b) 2s self timer
c) achieve best focus on f4, then switch aperture to f8 without using focus
Now there is one other thing: When I'm on F8 I can achieve better center sharpnes when I slightly pull focus ring but then my corners looks much softer than on F4 :/
Should I try 3rd copy of this lens or is this normal ?
I've received another copy of 24-105 F4. It is much better than the first one, but there is something wrong with it. I've tested all focal lenghts on F4 and F8. On every single shot on all focal lenghts there is always the same situation:
Center is much sharper on F4 than on F8, corners are sharper on F8.
