Re: Digital questions: was: Re: Is the New LX Going to Be a Digital Camera

[Doug Franklin]

On Fri, 27 Jul 2001 06:30:28 -0600, William Robb wrote:

> What I would like to know is what sort of
> dynamic range in stops (a concept I do
> understand) does a CCD chip have? Is it variable
> based on software or is it hardware limited?

Based on the ads I've seen for film scanners, it appears that Dmax
(maximum dynamic range) for CCDs typically runs from about 3.0 to
nearly 4.0 ... some scanners actually claim Dmax of 4.0 or a little
more, but I have to wonder if those are marketing numbers.  IIRC, the
Dmax scale is log-10 rather than log-2 like stops. So, Dmax of 3.0
would translate to 9 or 10 stops (log2(10^3)) while a Dmax of 4 would
translate to 12 or 13 stops (log2(10^4)) of range, assuming the CCD
response is linear.

TTYL, DougF

-
This message is from the Pentax-Discuss Mail List.  To unsubscribe,
go to http://www.pdml.net and follow the directions. Don't forget to
visit the Pentax Users' Gallery at http://pug.komkon.org .