parastratos

Thanks a lot, this was really helpful.

I just mounted a fujinon 27mm lens to my xt20 and I noticed that it makes a constant sound because it keeps trying to auto focus. My 16-50 lens didn't have the same behavior. I have disabled the pre-af option in non-auto mode but I don't have access to this option in auto mode. I upgraded the body's firmware but didn't see any difference... So I have some questions: Is this normal for a lens to have this behavior? Can I somehow disable the pre-af on auto mode?