Digital BW, The Print

Martin,

You wrote:

>...
>One thing that does happen is when applying an RGB separation curve like
>Paul's, is some "combing" or lose of the image's data. Generally this is
not
>a problem but if you already have combing in the image from strong
>adjustments the addition of the separation curve can push it over the edge.

>[One]... solution would be to work in 16-bit mode rather than 8-bit mode
...

Here is a second possible solution.

I used to have the problem of lost grayscale in another setting, and I
discovered a workflow that actually fills in the holes in the histogram
"comb" with reasonable success.  It may sound a bit weird, but give it a
try.  Here is the procedure (that I just suggested another person try):

To "fill in the gaps" of a histogram, for example, to smooth skies, etc., by
filling in tone values where there are gaps, try this procedure.  The basic
idea is to make copies of the file in question -- perhaps in this case after
the application of the curves -- and then use blur on one copy and sharpen
on the other copy.  (These functions actually fill in the histogram "comb" a
bit.)   Then combine all the copies (apply, normal mode, 50% for the first
combination, 33% for the third image).  By using both blur and sharpen on
different copies, the visual effects of the sharpening and blurring are
offset.  It might be about as effective to just make one copy and use blur
on it, and sharpen on the original.

Give it a try and let us know if it helps.

Paul
http://www.PaulRoark.com