12-23-2010, 10:37 PM
[quote name='popo' timestamp='1293128822' post='5159']
Just thinking generally... the camera will focus wide open regardless of the actual aperture used. f/2.8 will increase the depth of field and possibly mask small focus errors. Looking at the 50mm f/1.8 II review, there is some longitudinal chromatic aberration, caused by the focal planes of different wavelengths of light not coinciding exactly in the same plane. I guess, if the subject or lighting was skewed towards some colours more than others, the AF sensors would only see that and might pick a different focus point. Even if that were the case, I don't know how strong an effect it would be.
I could test it some time, but it probably wont be soon.
[/quote]
Just thinking generally... the camera will focus wide open regardless of the actual aperture used. f/2.8 will increase the depth of field and possibly mask small focus errors. Looking at the 50mm f/1.8 II review, there is some longitudinal chromatic aberration, caused by the focal planes of different wavelengths of light not coinciding exactly in the same plane. I guess, if the subject or lighting was skewed towards some colours more than others, the AF sensors would only see that and might pick a different focus point. Even if that were the case, I don't know how strong an effect it would be.
I could test it some time, but it probably wont be soon.
[/quote]