Warp <war### [at] tagpovrayorg> wrote:
>   I don't remember if this has been discussed before, but the new gamma
> handling might cause headaches when using color maps and other interpolated
> maps.

  Here's an actual scene where I used the pattern in question:

http://warp.povusers.org/images/glassblob1.jpg
http://warp.povusers.org/images/glassblob2.jpg

  Both of the images were rendered with pov3.7 beta. The difference is
that in the first one I used 'assumed_gamma 2.2', while in the second
one I instead applied 'gamma 2.2' to the individual colors and default
ambient.

  The gamma correction doesn't only affect the color gradient on the
floor, but naturally also the shading on the spheres. The end result
is that the second image ends up being much brighter (because the
color gradient on the floor is much brighter) and having much less
saturation/contrast than the first one, making it duller and "washed
out", even after all the used colors are matched with the proper gamma
correction. The transition between the illuminated and dark sides of
the spheres is also much more abrupt (due to gamma correction).

  The brightness increase is not necessarily all that problematic, but
the visible reduction in saturation/contrast is. It makes the image much
less vivid. The first image may be significantly darker, but the higher
saturation/contrast makes it vivid and lively.

  Obviously it's basically impossible to replicate the first image in
pov3.7 without using 'assumed_gamma 2.2', which will then affect all
colors. This may be a problem for many.

-- 
                                                          - Warp

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