Digital BW, The Print

Alessandro writes:

> I rely on numbers, i.e. open Photoshop levels
> and press AUTO.

You can set the white and black points visually by using the Curves dialog.
Shift the curve way to the left, then set the black point.  Then shift it
way to the right, and set the white point.  Shifting the curve makes it much
easier to see the darkest and lightest spots in the image, and the curve is
reset each time you set the white or black point.

Another way is to use the Levels dialog.  For each color channel (if working
in color, otherwise not applicable), move the sliders to exclude the flat
area at the top and bottom of the image, if any.  This preserves a little
more detail than the auto-levels operation, which clips the two ends.

I'm not sure whether curves or levels are best.  I use both, mostly on
intuition.