Time to be with your loved ones

Time to be with loved ones

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1
vote
2answers
73 views

How does aperture/DOF affect continuous autofocus?

When the autofocus system is deciding to adjust the focus, say in a situation of the subject getting closer to or farther from the lens, does it take into consideration the current depth of field, ...
11
votes
4answers
549 views

Why aren't lenses designed with extra large apertures for autofocus beyond what's used for imaging?

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. ...
2
votes
1answer
348 views

autofocus and maximum aperture of 60D [duplicate]

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 ...
6
votes
6answers
1k views

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 ...
35
votes
3answers
9k views

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 ...
11
votes
2answers
4k views

Why does Canon and Nikon limit or disable autofocus beyond certain f-numbers?

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 ...
4
votes
2answers
955 views

AF-D vs AF-G: is the aperture ring necessary?

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 ...
10
votes
4answers
472 views

Focusing on moving target with large aperature?

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 ...