Dynamic range and bit depth
Dynamic range and bit depth
- Subject: Dynamic range and bit depth
- From: Roger Breton <email@hidden>
- Date: Wed, 06 Dec 2000 08:29:37 -0500
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Andrew Rodney wrote
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ADynamic range and bit depth have absolutely no correspondence. You can have
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a 10 bit scanner with a dynamic range of 3.8 and a 12 bit scanner with a
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range of 3.3. Completely different spec's. Also be aware there is no
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universally accepted way of measuring dynamic range.
I have to disagree with you, Andrew: dynamic range and bits are completely
interrelated.
A 10 bit scanner can represent 1024 discrete levels (2 to the 24 power)
which corresponds to a dynamic range of 3. 12 bits of data, on the other
hand, yields 4096 discrete levels which is somewhere between 3 and 4, in
dynamic range. 14 bits of data (2 to the 14 power) is all you need to
accurately represent the 10,000 discrete levels of a dynamic range of 4.
I agree this is aside from any implementation issues and marketing hype on
the part of hardware manyfacturers.
I would suggest you turn to Phil Green's excellent "Digital Photography"
book, recently published by Pira (ISBN 1-85802-207-X), for a short, to-the-
fact discussion on this concept (page 29, last paragraph).
Regards.
Roger Breton
Quebec Institute of Graphic Communications