AF with oncoming subjects

Duncan C wrote:

I have a couple of issues with your post. First, viewfinder based AF uses phase detection and a small number of focus points. The camera is not evaluating thousands of points of data. Just a few dozen. That shouldn't be beyond the capabilities of a modern processor.

Second, predictive autofocus is supposed to calculate speed and direction, and match it. The camera should be able to figure out that there is a subject approaching at a given velocity, and set the focus to track its motion as it comes in, while fine-tuning the focus change as it goes.

I don't know about limitations on the AF motor. I would think an AF-S lens would be able to track focus pretty darn quick however. That's a major point of the "ultrasonic" focus motors in these lenses. There's a lot less parts to move, so the focus is FAST.

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Regards,
Duncan C
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