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Old May 21, 2003, 9:19 AM   #11
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Hi Barthold,

No, there is no degredation of performance in low light conditions. The amount of light gathered is dependent solely on the lens. The smaller sensor simply uses less of the circle of definition than does a full frame sensor or 35mm film or transparency media, but the light is distributed across the entire circle of definition and sampling a portion of it doesn't diminish the relative intensity.

Think of it like this. You take a picture of an evenly lit pure white object and fill the frame. Now sample any portion of the object captured on film or with a digital sensor and the intensity and hue are consistent throughout.

Best regards,

Lin
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Old May 21, 2003, 11:10 AM   #12
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Barthold

I think the better/more interesting question is not about the crop, but the photosites in the sensor. How do they compare (in size and sensitivity) to film? (What film? I know, an unanswerable question as stated.)

As Lin says, it's not the size of the sensor which would make it more or less sensitive than film. It's a question of how much light gets to the sensor (i.e. the lens' abilities) and the sensor's ability to sample that light.

What I've wondered is how does the size of the photosites effect the picture? I know it effects noise, but a larger photosite would cause more light to be sampled down into 1 pixel... which I can't see as being very good. How do the photosites compare to... whatever it is that reacts to light in film (forgot the name!)

I'm not really sure I know enough to ask the question, its just something my brain has been tossing around.
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Old May 21, 2003, 11:37 AM   #13
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Hi Lin,

The key then, as you pointed out, is the amount of light per unit area, not the amount of light that the lens captures.

Barthold
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Old May 21, 2003, 11:54 AM   #14
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Hi Barthold,

Yes, that's why it's possible to have very fast but tiny lenses with the consumer cameras.

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Lin
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