Getting action shots - focusing and framing advice needed

[Overread]

No such thing Runnah

wfooshee - true planes are going a lot faster; but relative to your camera the difference isn't as great. When I'm at 200mm at most and the horse is coming toward me a few moments and the position of the horse has quite significantly changed. I totally get that I don't want the camera grasping at the fence or background in a moments slip of the AF position; but at the same time do I really want it to be going at a slower pace for its requisition of a focusing point if I've got shoulders, neck, head all coming toward me?

weepete - probably a good point - I tend to do this mostly in manual mode with a quick shot to check exposure (so long as I'm only getting a tiny amount of the blinkies on the whites of a jump that's generally ok). I'll keep it in mind for the future though certainly as if I do this in really good light (like outside!) I'm very likely to shift into AV mode and let the camera do some work for a change.

 

[wfooshee]

wfooshee - true planes are going a lot faster; but relative to your camera the difference isn't as great. When I'm at 200mm at most and the horse is coming toward me a few moments and the position of the horse has quite significantly changed.

I see what you're saying, and while a couple of hundred yards to a half mile or so is still at the upper end of the focus range and not that big a motion on the focus ring of the lens, when it takes less than 2 seconds to cover that distance it's still a nice job of tracking! The sneak pass aircraft in the Blue Angels demonstration is approaching at higher than 700 miles per hour. In the last second before his closest approach he is 2 tenths of a mile away. As he passes immediately in front, he's just over 600 feet away. I'll get 6 or 7 shots in that span, and they're perfect. the camera doesn't switch to the trees in the background or the crowd in the foreground.

I totally get that I don't want the camera grasping at the fence or background in a moments slip of the AF position; but at the same time do I really want it to be going at a slower pace for its requisition of a focusing point if I've got shoulders, neck, head all coming toward me?

But it doesn't go at a slower pace on the object it's tracking. The setting has nothing to do with actual tracking, it only slows down the switch to a very different focus distance. Exactly how the camera determines what "very different" is I couldn't say, maybe it's a percentage difference, but during a momentary slip and re-acquire of the subject, the subject will not be different enough in focus range to be affected by this setting and will be refocused instantly. During that momentary loss, with the waiting period set, the camera is actually holding focus and looking for something close to the same distance it last had so it can continue tracking.

 

[Derrel]

Wfooshee has made three very clear, cogent posts about what "Focus Sensitivity" actually does. It's what Nikon calls "Lock-On". And because both companies chose an absolutely horrible name for this control/feature, it is mis-understood perhaps 95% of the time. My experience is that when the subject is small, and the focusing area in use is small (or a single AF point), that having this sensitivity set to its highest level can lead to utterly disastrous "searches", Drop-offs, and "flyers", as the AF system leaves the presumed target wayyyyyy too readily. When the subject is larger or there's a multi-point AF grouping in use, and the subject is what I call a good focus target, then there's less of a tendency for the focus to be lost than there is on a small subject. I wish to hell that this control had been named something MUCH more appropriate, like "Give Up and Hunt for Focus Delay", or "Back Focus Like A Bastard At Will Delay Value"...something more descriptive...

 

[jerrydnow]

Canon EOS 7D DSLR field review.

Reading this though suggests that my earlier estimation might be the more correct. You know I never really appreciated but darn it Canon didn't make this easy - its just one little slider!!