> > AFAIK: There are two parts: the assumed_gamma and the display_gamma.
> > Assumed_gamma is used internally during the raytracing, which is the
reason
> > why it should be set to 1.0: so that the internal calculations are done
in
> > the correct, linear colorspace.
> > Display_gamma is applied *after* the raytracing, and is meant to ensure
that
> > when *rendering* the image on different PCs with different gamma, the
output
> > *looks* the same.
>
> That's not correct, the gamma correction is performed exactly as
> described in the docs, section 3.3.3.3.

Hm. Correct me if I'm wrong again, but I find the description a little
confusing. If I use assumed_gamma in my scene, THEN some sort of
gamma-correction will be applied to the final saved image, otherwise, no
gamma-correction.
The gamma-correction itself is dependant on the values for assumed_gamma and
display_gamma, and this also gets saved to disk. Unless you use PNG, the
file won't know its gamma, and thus, will probably end up looking different
on different monitors.

Why then should we use assumed_gamma of 1.0?

I've also just tested using display_gamma 1.0 and assumed_gamma 1.0, and
then, the image gets *really* dark. I assumed (probably wrong, though) that
both at 1.0 should result in no change from raytracing input to file-output.

And if I leave out assumed_gamma (hence no gamma-correction, I'd think), the
image gets even darker (this should be expected if display_gamma is really
2.2 but only set to 1.0, I guess). Display_gamma 2.2 and no assumed_gamma,
again, image is darker than original.
This stuff is all pretty confusing, I don't get what I expect. Which is
probably due to some misunderstanding on my part...

How about someone explains (without that much mathematical stuff as in the
docs) how assumed_gamma, display_gamma and file-saving works? Default
settings, gamma-correction (when and how it is applied)...

-- 
aka "Tim Nikias v2.0"
Homepage: <http://www.nolights.de>

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