martinairyyz
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Is Auto-focus On Digital Cameras Worse In Dark?

Sun Feb 01, 2004 8:27 am

The title is my question!


Martin
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wietse
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RE: Is Auto-focus On Digital Cameras Worse In Dark?

Sun Feb 01, 2004 8:33 am

Yes.

AF judges the scene based on differences in contrast (ie. lines) If there is little light, contrast is lower. Therefore the AF sensor has a harder time picking out the contrast differences.

Wietse
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Staffan
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RE: Is Auto-focus On Digital Cameras Worse In Dark?

Sun Feb 01, 2004 8:36 am

Yes, the better contrast you have in a scene, the better the AF will work. If there is no contrast where you are trying to focus (such as a flat wall or a dark room) then the AF will have difficulties telling what's in focus, and what isn't.

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Vulindlela
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RE: Is Auto-focus On Digital Cameras Worse In Dark?

Sun Feb 01, 2004 8:49 am

But is it worse on dslrs compared to film cameras? Is that the question?
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wietse
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RE: Is Auto-focus On Digital Cameras Worse In Dark?

Sun Feb 01, 2004 8:55 am

Ah ok.. uhm that all depends.. actually no matter what type of camera, it all has to do with the AF unit. So if you put the Canon 1D AF unit into a 10D, it will AF the same.

Most of the time costs of a super AF unit are too great for a type of camera and AF is less potent on those models. Plus cheaper digicams dont need the advanced AF unit of the 1D.

But to answer the question: There is no direct correlation between digicam/film and AF.

Wietse
Wietse de Graaf
 
hkg_clk
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RE: Is Auto-focus On Digital Cameras Worse In Dark?

Sun Feb 01, 2004 2:45 pm

I think for consumer digicams, AF is definitely generally slower in the dark than film cameras.

DSLRs are a different story. It depends directly on the autofocus system.

hkg_clk
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JeffM
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RE: Is Auto-focus On Digital Cameras Worse In Dark?

Sun Feb 01, 2004 2:47 pm

Have yet to have a problem focusing in the dark with my Nikons...film or digital. Have shot in complete darkness at over 100 yards with no issue focusing, of course you can always manual focus if your having issues.
 
sfilipowicz
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RE: Is Auto-focus On Digital Cameras Worse In Dark?

Sun Feb 01, 2004 8:35 pm

The Sony DSC-F717 and I think the F707 have a built-in laser that projects a matrix on the object you want to photograph, the camera can then focus very good. Allthough this is only for objects the are not too far.
 
diezel
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RE: Is Auto-focus On Digital Cameras Worse In Dark?

Sun Feb 01, 2004 9:56 pm

Sfilipowicz is right. Some cameras and flashes have a little lamp on it which is used to illuminate the subject you are shooting. The AF system locks on to that light. It works well up to about 4 meters and even in complete darkness. But You still need some contrast in you subject.

I have a Nikon D100 which has a (very bright) white light to help focus the camera. It works well but some people don't like to have that light shining in their eyes as it is blinding. My SB24 flash has a red focus light which is far more friendly to the eyes.


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