Nill Toulme wrote:
It could, but apparently it does not:
\"The three important AF related Custom Functions introduced up to now, C.Fn III-2 Tracking Sensitivity, C.Fn III-4 Tracking Method, and C.Fn III-8 AF Point Expansion are associated such that each of their settings exert an influence on the workings of the other functions. For example, if AF point expansion is turned off, the AI Servo AF tracking method will not function.\"
See also the \"Two types of AF tracking methods during area expansion\" table on that same page.
While we\'re (sort of) on the topic — is there any difference between ROF and CFIII-8-3 other than that the former always starts with the center point, but with the latter you can start from a selected point other than the center?
Nill
Nill,
I\'m not sure that the language in the first paragraph of what you quoted is quite accurate. I believe that, if expansion is turned off (via CF III 8), the method of tracking (CF III 4) is altered (in the way that I explained above), but I don\'t think it is disabled/not functioning.
Practically speaking, I think that the difference between using all 45 points and using area focus via CF III 8 is that you can start with a manually selected point with area focus, but you must start with the center point with auto selection. However, theoretically, with area focus, at any given instant there is a cluster of only 18 focus points available for use, but, from one moment to the next, that cluster can shift to a different group of 18 available points. So, theoretically, if the subject shifted, say, from a far left focus point to a far right focus point in an instant, that far right focus point might not be active. Practically speaking, I\'m not sure how often that is likely to happen. In any case, I\'ve never been a fan of auto selection of focus points, and I don\'t see myself using either auto selection or area focus very often. On the other hand, I\'ve been very positively impressed with how well expansion to surrounding points works and how reluctant the camera is to be fooled by even a busy background with expansion to surrounding points.
Les
Mar 03, 2010 at 04:23 PM
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