After seeing the aliasing and false color with the Otus 85 wide open on the Sony a7RII in yesterday’s post, it’s reasonable to ask how much the lens aberrations at f/1.4 are reducing aliasing and false color, even if it’s obvious that they are not eliminating them.
To do that, we can look at a series of similar images made at f/2.8, which is the Otus 85/1.4’s sharpest on-axis aperture.
The images are slightly darker. The reason for that is the way the a7RII meters, combined with the strong light falloff that the Otus has wide open. The camera sees the darker edges and corners at f/1.4 and opens up to compensate.
At one extreme of defocusing:
At the other end of the rail:
At a few places in the middle:
It is interesting that the places on the rail where there’s the most false color are not necessarily the places where there’s the most monochromatic aliasing.
My conclusions are that the aberrations of the lens wide open are making little difference in the visible aliasing.