Digital BW, The Print

> From: julie stapen [mailto:jsstapen@...]
>
> I use the 10D and have seen slight posterization in
> B&W's as well. I'm confused on all the terminology
> though... what is 16 bit in PS-CS? I'd love to try...
> Do you first change it to grayscale in photoshop and
> then convert it to 16 bit color? I use photoshop 7 on
> mac osx. Also I've seen a lot on using curves, is that
> better than using levels?

First of all, you have to shoot in raw mode, since JPEGs are only eight bits
per channel. Second, since you only have PS7, you'll probably be doing raw
conversion outside of PS. (The new PS CS has a very good raw converter
built-in.) When you do the conversion, save to 16-bit-per-channel TIFF. (It
might be called 48-bit TIFF.) When you open this in Photoshop, you'll be in
16-bit mode, and you'll notice that lots of editing features are disabled.
PS CS fixes this, which is a good reason for upgrading. But you can use
Curves, Levels, Hue/Sat, etc., and as long as you stay in 16-bit mode, you
shouldn't see any posterization.

Curves is certainly more versatile than Levels, but it doesn't have a
built-in histogram. In 16-bit mode, there's no harm in using one, then the
other. I usually use Levels to get rid of most of the wasted space on both
sides of the histogram, boosting the contrast somewhat. Then, I go into
Curves, and get the precise tonal shape that I want, often with some sort of
contrast-enhancing S-curve.

--

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