"scott" <sco### [at] scottcom> wrote:

> The output file should consist of orange background pixels of 255,128,64,
> and the right box should be twice as bright as the left box *on my monitor*
> (ie utilising whatever gamma setting I have, could be 1.8 for mac or 2.2 for
> PC).  This is the expected output.
>
> If I render with no gamma correction, I get the expected result: correct
> background colour, and the actual pixel values of the right box are twice
> the left box.

I assume you mean, when using no assumed_gamma at all?

On a PC with a default 'system' gamma-correction of 2.2, and with POV for
Windows' display_gamma also set to 2.2, my understanding is (and visual results
indicate) that using assumed_gamma of 2.2 or leaving it out entirely produces
the same rendered image (a .jpeg or Windows-specific .bmp image, with no
'embedded' gamma information.) That would be correct behavior, if I understand
POV's gamma documentation. Most problems with erratic color and 'washed-out'
appearance come from changing the assumed_gamma, so that it no longer matches
the rest of the set-up. The 'old' POV documentation, with its near-insistance
on using an assumed_gamma of 1.0, is misleading in that regard. (I believe that
the documentation concerns two things: for letting others render your scene file
on their own systems --although I still don't understand using assumed_gamma of
1.0 for that--and for rendering your own POV scene as a .png image, thus
embedding a necessary(?) assumed_gamma of 1.0 into it. I never use .png for my
own output, so I don't know for sure.)

Ken W.

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