Alec_Burgess

@rollab:
Interesting variant on your technique ...
Take any picture. Dup background and change Opacity to 50% - result is gray image.

Nudge copy on x/y: result bas relief

Copy base to dup-2, copy dup-1 to dup-3 then desaturate dup-2 and dup-3. Resulting layer stack
dup-3 B&W, opacity 50%, nudged x/y
dup-2 B&W, opacity 100%, not moved
dup-1 color, opacity 50%, nudged x/y
base color, opacity 100%, not moved

Turning off and on layers 2,3,4 gives interesting variants. I like background and dup-3 ON - gives bas relief with tinge of colour. see Flamingos-orig and Flamingos-bas-relief on my page.