I have seen somewhere- but not sure where, about the centre focus point being accurate at f2.8?
I am sorry to be so vague with my question, but can anyone give me more information as to what this means?
If your len's have a smaller aperture than f2.8, is focus no longer accurate?
How accurate are the other focus points that are not in the centre
What's the difference between a cross focus point and otherwise?
I would appreciate it if anyone can shed some light on the above for me,