Historically, designing large-aperture lenses has been difficult because correcting the optical aberrations that arise from large apertures requires complex designs and very large amounts of glass. ...
Possible Duplicate: What are the aperture limits for autofocus on Canon DSLR cameras? It is mentioned on page 79 of the EOS 60D manual that the center point AF is twice as accurate at ...
Is it important that the Canon 1DX isn't specified to autofocus with lenses slower than f/5.6? [closed]
Seeking the lens market AND the related info WRT Canon 1D X, I found some things which seems concerning: 1st, a note from Canon's Chuck Westerfall (see here) saying: “AF is unavailable on the ...
What apertures are required to enable autofocus, including cross-type or high-precision focusing, on Canon DSLR cameras?
This is a follow-up to Why does Canon and Nikon limit or disable autofocus beyond certain f-numbers? I'm doing this to separate the AF aperture requirements from the linked question above. My goal ...
One thing that I've noticed with Canon DSLR camera is they will disable or limit autofocus when the lens is below certain aperture values, which are specified in my answer to What are the aperture ...
I just purchased a Nikon D7000 with an 18-105 f/3.5-5.6 AF-S lens. I'm also looking at purchasing a lens around the 200-300mm focal length range, and I found the 70-300mm f/4-5.6 AF lens. As far as I ...
I have read about difficulties getting focusing right when using a large aperature (because of depth-of-field issues). If I am using a fast prime wide open (say F1.4 or F1.8) to shoot a target in ...