Digital BW, The Print

> > > > I don't know quite what you mean here...we only measure
> > > relative values, as
> > > > in 2 times, 3 times, 4 times....1000 times...only integer
> ratio values.
> > >
> > > What he is saying is that the CCD's voltage is analog and therefore
> > > infinite.
> >
> > That's a misnomer.  Analog is not infinite.  It is limited by noise, and
> > that is what dynamic range is...the largest signal over the
> noise.  If you
> > have a maximum 6V signal, and your noise level is .003 volts, you have a
> > dynamic range of 3.3.
>
> okay, well why don't you make a CCD with more volts and less noise?
> You can't put aside our theoretical arguments by saying a CCD has
> noise.

What "theoretical arguments"?  I'm talking reality.

> > > Why can't, using your above example, someone make a scanner using the
> > > more sensitive 14bit A/D converter on the less sensitive CCD from the
> > > 10bit scanner. (I assume you mean sensitive as in the ability of the
> > > CCD to judge brighter or darker tones)  This should allow more tonal
> > > information over the same Density Range.
> >
> > Nope.  The values you get out of the CCD/AD are RELATIVE.  2 is twice as
> > bright as 1, and 4 is twice as bright as 2, no matter what CCD
> or A/D you
> > use.
>
> Why does it have to be that way though?

It doesn't, but it's designed TO be that way.  It is easier TO design it to
be this way.  What advantage would you see to doing it some other way?

This design makes things VERY easy, since the data out of the A/D pretty
much matches integer density ratio values.