Hello POV-folks!

My understanding about gamma is now the following (I made an unforgivable
mistake in my entry for last IRTC entry ... shame on me): if your monitor
is calibrated (ie the operating system compensates your monitor's weakness
on low grays by applying color correction using an appropritate color
profile, typically the most used sRGB color profile) then your system can
be considered as linear, with an overall gamma of 1.0. IS THIS TRUE? If so,
this means that if a pixel has 10% gray value, then your monitor displays
10% of brightness, whatever the file format used.

I guess that ALL not-too-old systems perform this correction. So, according
to me, I would rather agree with Tim, and POV scenes should be designed for
linear display and linear values in output files. This means, if I am not
too wrong, that either both assumed_gamma and Display_Gamma should have the
same value (typically 2.2) or no "assumed_gamma" directive should be in the
code.

The POV documentation recommends a value of 1.0 for assumed_gamma: So I
would say that Display_Gamma should also be set to 1.0. Otherwise the
images would appear too bright (for example the shadowed area (defaulted to
10% of brightness).

       Bruno

Post a reply to this message