Faster autofocus

A630Lover

115

« on: 25 / May / 2008, 08:27:21 »

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Hi!
I already posted a topic in another thread, so I will try to explain without repeating myself too much...
I noticed that when I was using the "pets & kids" scenic mode on my A630 (dunno if it exists on other cams), the autofocusing process was, let's say twice as fast as the normal focusing speed. That is due to the fact that the camera limits the "searching range", that means that instead of focusing from (let's say) 10 cm to infinity, it focuses from 1 meter or so to infinity.
That's for the good news. The bad news is that this 'focusing particularity' only works in that particular scenic mode.
I wondered if it would be possible to make an option in the chdk menu in order to be able to choose this option in whatever mode.
Thanks for your answers.

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vine

124
A560

Re: Faster autofocus

« Reply #1 on: 25 / May / 2008, 08:53:48 »

Quote from: A630Lover on 25 / May / 2008, 08:27:21

That is due to the fact that the camera limits the "searching range", that means that instead of focusing from (let's say) 10 cm to infinity, it focuses from 1 meter or so to infinity.

Do you have any conclusive evidence of this or is it mere speculation?
I couldn't observe any difference in focus speed on neither A560 nor A570.

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A630Lover

115

Re: Faster autofocus

« Reply #2 on: 25 / May / 2008, 12:02:29 »

Well, I have. When I try to focuson a subject closer than, say 1m or so, the camera doesn't lock focus. In the normal mode, the camera can focus up to 45 cm (I checked) from the subject.
That's a method commonly used on some slr lenses that have no silent wave focus motor. If you shoot a subject that is quite far, you simply enable the limiter (at least, it is called that way in french, I think :p )
so that the camera does not have to "hunt" the entire focusing range.

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