Digital BW, The Print

> From: David Sinai [mailto:dsinai@...]
>
> Shouldn't there be a different histogram once the file is converted
> to 8 bit? Going from 16 bit to 8 bit means that the tonal range has
> been reduced, correct?

The tonal range is the same, so the histogram remains the same. The only
thing that's changed is the fineness of the steps. In 8-bit mode, each step
is only 1/256 of full scale. If you do a curve in 16-bit mode, you'll still
have a clean histogram, but if you do a curve in 8-bit mode, some of the
steps, which were 1/256 of full scale, will inevitably be turned into 1/128
of full scale, which will show up as missing lines (combing) in the
histogram. In some cases, this can correspond to faint but visible
posterization in the print.

If you have PS CS, you can stay in 16-bit mode to the end. If not, just make
sure you do your major curve adjustments in 16-bit mode, and do lesser
tweaks (e.g., sharpening) after converting to 8-bit.

--

Ciao,               Paul D. DeRocco
Paul                mailto:pderocco@...