If shooting at f/22, is a fast 1.8 lens still considered fast?

Started Apr 17, 2011 | Discussions thread
noirdesir
Forum ProPosts: 11,222
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Exactly, *Canon* cameras but only Canon
In reply to edwardaneal, Apr 22, 2011

edwardaneal wrote:

here is another write up on phase detect autofocus - specifically the Canon system

http://www.zen20934.zen.co.uk/photography/Canon%20AF%20System.htm

and a quote from it

"Accuracy

When the camera determines how far and in what direction the lens must move to cancel the phase difference, it does so within a tolerance of "within the depth of focus" of lenses slower than f2.8 (down to f5.6) or "within 1/3 of the depth of focus" of lenses f2.8 and faster.

so finer adjustments with lenses of f/2.8 or faster

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My kit - D200, 10.5mm f/2.8D, 35mm f/1.8G, 50mm f/1.4G & 70-300VR
SB800, SB600 and other misc lighting equipment

Lenses worth mentioning owned and sold– 12-24 f/4, 17-55 f/2.8, 35-70 f/2.8, 80-200 f/2.8, 20mm f/2.8, 35mm f/2, 50mm f/1.8, 50mm f/1.4D, 60mm f/2.8D, 85mm f/1.8, 105mm f/2D-DC, 180mm f/2.8, 300mm f/4D-ED

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