Digital BW, The Print

Hi Truman,

> A CCD counts photons and produces a voltage as a function of the number
> of photons detected over a time window (integration time). So while it
> is probably a misnomer to call anything associated with CCD's analogue,
> the effect is similar if it is done correctly.

Hum...  Gain is a multiplication factor, increasing exposure is a shift
(called an offset).  One will expand the range, the other will simply shift
it.  Right?  Basically, there are three things you can adjust in a signal.
Gain, offset and linearity.  Gain is a multiply, offset is an add, and
linearity is an add as well, but is on an individual value, not an overall
value, like a LUT (Look Up Table).

> I would much prefer an integration time based on the film and then gain
> adjustments of the output voltage prior to the analog to digital
> converters - with some care taken as not to increase the background
> noise level.

Correct.  That is exactly how I have done it, and noise is the operative
problem.

Regards,

Austin