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Old Sep 13, 2003, 4:08 PM   #1
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Default slow digi-compacts

Hi,
can anyone explain to me why digital compacts are so much slower than analog ones. At least things as focussing should be the same!
What is different for the digital pro-cams, those are as fast as the film pro's.

Where can i find background info on these topics?

thanx
Charles
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Old Sep 13, 2003, 4:23 PM   #2
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It depends on the compact camera. Some use a fixed focus (so focus times are nil).

Also, most consumer digital cameras use a contrast detection focus system, examining areas of the frame for enough contrast to determine focus. They also have to add a step to determine proper white balance (by examining the colors in the photo, and adjusting them for accuracy).

Metering/Exposure Settings is also more critical with a digital camera - since digital cameras don't have the dynamic range of film cameras. They must adjust the sensitivity of the CCD via ISO Speed for different lighting conditions (in addition to the shutter speed/aperture settings).

All of these things take time (although, digital cameras are getting faster and faster at it nowadays).

SLR's use a TTL Phase Detection Focus System instead (which tends to be faster than a Contrast Detection System). Some new cameras are going to hybrid Phase Detection/Contrast Detection Systems, to give them the best of both.

Faster and Faster processors should improve all cameras in this department.
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Old Sep 14, 2003, 12:31 PM   #3
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That doesn't explain why my $100 point-and-shoot film camera focuses much faster than my $300 digital camera. I think that was the point of the original question.

True, the film camera doesn't need to adjust for white balance, but how long does that take anyway?
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Old Sep 14, 2003, 2:14 PM   #4
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Quote:
That doesn't explain why my $100 point-and-shoot film camera focuses much faster than my $300 digital camera.
I thought Jimc covered it. Focusing is not the only thing that the digicam processor is doing to record a pic. If it was, then I'd expect the focus electronics to be as fast as in the film cam.

When you buy a digicam you're getting technology trade-offs. They could put in faster processors,much larger and faster buffer cache, and compact nuclear batteries to run it all - but these are new products and the manufacturers want some sales up front before they drip feed the camera that works as good as a film cam!

Think about the early computers running Windows. The software demands on machine resources were always ahead of new processors, faster memory and architecture. Then Bill brings out XP and you need a better machine! Same with digicams. Suppose we aspire to 12 Mpix. You'll get it first but it may be slow, then the next evolution will be faster. VOX
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Old Sep 14, 2003, 4:29 PM   #5
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So that could probably mean that my $100 film camera has better auto-focus system than my $300 digital camera? The trade-off is probably slower focusing for the better optics and higher picture quality. Yes, my 3MP digital camera gives results I never dreamed of with my film camera.
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