Ok, I think that AF cameras send out a IR square wave and then look for
reflections of the same frequency as the square wave. The difference in phase of
the reflected light and the source light can be used to calcuate the difference.
Is this what you mean?
Why would this have a problem in low light conditions? Since the camera carries
it's own little IR source...
Or maybe something else is meant by phase?
Date: Tue, 28 Jan 2003 16:42:24 +0000 (GMT)
From: julian_davies@xxxxxxxxxxxxxx
Subject: Re: [OM] OM-30 Question
Works like a modern AF camera - Phase detection. Actually works better than I
expected, but only down to dim - ish conditions, not really what I would call
low light.
It's not AF - for that you need the AF zoom, but just indicates whether the
centre - spot area is in focus or not, and which way to turn the distance ring.
Then emits a really annoying beep when you have done as commanded (you can turn
that bit off, fortunately)
The bit that goes beep can also trigger a winder / MD
With a bit of work, they could have turned this into something really useful.
Julian
Julian
--
Clendon
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