Andre, if I understand you, that's along the lines I was thinking. Regardless of bit depth of the A/D, Assuming all CCD's and everything else is equal, the brightest white will be the biggest number on each A/D correct? This seems to make perfect sense to me as a programmer, but I'm not up with all the optical stuff.

Aaron

Andre, I'm not following what your saying. Are you saying 8 bit and 16 bit image files have the same dynamic range?

Yes Jeff. The non adaptive CCD dynamic range is the range between the highest signal level (limited by a certain amount of distortion- "white clip" in video)and the lowest signal level (limitted by a certain amount of unwanted vs wanted signals- noise, glare..in cams ). This figure is seldon higher than 45 db in consumer camcorders. Maybe there is a confusion about how well a scene's dynamic range (80db and more) is being "packed"into the limited camers range. This subjective compression
performance is like I wrote (knee processing, gamma, ..) bitdepth dependent.

Even before processing the 16 bit file would contain more levels of gray (greater dynamic range) that are discernible to the eye than an 8 bit file.

Here http://www.fillfactory.com/htm/techn...df/oeepe99.pdf (PDF) is some info on CCD (and CMOS) dynamic range. IMEC is a Belgian micro electronics research center where I used to be a member of the scientific advisory commitee for several years.

Thanks Andre, I'll look that over after classes this afternoon. You may be interested in Norman Koren site and his discussion on tonality and dynamic range.

Interesting article. Although dynamic range is a well defined ratio, the " hidden dynamic range" approach is a good idea that kinf of explains what I wrote before: using high bitdepths allows manipulating (mainly expand) "hidden" parts in the analog signal.