Digital BW, The Print

> > But the histogram IS an 8 bit histogram...  It should look the same,
> > providing no tonal adjustments are done, and I don't believe simply
> > converting from 16 bit to 8 bit should do that...it only "lops" off the
> > lower 8 bits.
>
> Photoshop shows all histograms as "8 bit."

Exactly what I was pointing out.

> So when you view a Histogram in high bit (what
> Photoshop calls 16bit), you're not seeing what is really going on in that
> Histogram.

Why not?  You SHOULD be seeing only the top 8 significant bits of the image
file.  What else would it do?

> But you still have all the data in that file to
> manipulate. Once you
> convert to 8 bits per color (on a copy), now you are seeing the "real"
> distribution of the 256 levels of data. So the combs should be long gone.

I don't understand how that follows.  Unless either the 16 bit histogram
does not simply use the top 8 bits, or the conversion from 16 to 8 bits
somehow does some "processing", and not simply uses the top 8 bits, then
they should be the same.

> Bottom line is that when you have a high bit file and you
> manipulate it, you
> can use the Histogram provided but the preview showing the data
> or combing
> isn't accurate.

Why?  Specifically.

I think either you or I have a gross misunderstanding how the process works.
Perhaps you ought to outline exactly what you believe the histogram uses for
data, as well as how you think the 16 to 8 bit conversion process is done.
I have outlined how I believe they work.

Austin