Digital BW, The Print

> > > Simple answer; because you are scanning into a 16bit space and the
> > > scanner is not 16bits. That 3.7 worth of information is
> linearly placed
> > > along the 16bit histogram.
> >
> > Do you believe it is high bit justified, or just left low bit
> justified?  In
> > other words, does the scanner A/D give you a 12 bit value of
> 0101 1010 1010.
> > Does that end up in the 16 bit space as 0101 1010 1010 0000 OR 0000 0101
> > 1010 1010?
>
> What difference does it make? I was answering his question of why the
> raw scan doesn't fill the whole 16bit space. Luckily, we don't have to
> worry about what our images look like written out in binary.

It matters in how much space the values will occupy in the 16 bit space when
you get them from the scanner.  If the values are low bit justified, they
will occupy a smaller span than if the values were high bit justified.  Do
you know the answer?

> This does raise the question of, if the scanner is only capable of
> capturing 3.7 worth of information, why doesn't it automatically expand
> the range to fill the 16bit space, even in a raw scan.

I don't see that as significant, at least to me.  One reason is so you have
room to make tonal/endpoint adjustments.  You need headroom on top of the
data, below the data and between the data.  Just because you capture
something doesn't mean it's exactly what you want...you may want to re-set
the setpoints.  To what advantage does having the scanner/firmware/driver do
that operation for you, vs, you doing it in PS?  PS can do autoranging I
believe, which basically does what you are saying you want.  Why is this an
issue for you?