POV-Ray : Newsgroups : povray.general : strange problem with srgb color in light_source : Re: strange problem with srgb color in light_source Server Time
21 Jun 2021 11:47:21 EDT (-0400)
  Re: strange problem with srgb color in light_source  
From: Cousin Ricky
Date: 7 Apr 2021 12:33:54
Message: <606ddef2@news.povray.org>
On 2021-04-07 8:20 AM (-4), Kenneth wrote:
> Cousin Ricky <ric### [at] yahoocom> wrote:
>> If you are starting with a fractional literal such as <.7,.8,.9>, then
>> I'm with Ive: I don't know why you'd want to mess with non-linear
>> encoding at all.  Just start with a literal triplet that looks correct
>> with the rgb keyword.
> You're correct, of course. In my case, I was pulling in RGB colors from an *old*
> scene-- circa v3.5 or 3.6-- that I used to mistakenly run with an assumed_gamma
> of 2.2(!), just to get the rgb colors there to 'look' the way I thought they
> should. Some were of the form <.7,.8,.9>, some as like <104,230,75>/255. That
> was way before the 'srgb' keyword was introduced, and before I started correctly
> using assumed_gamma 1.0. So I'm updating the old colors to srgb now, to try and
> reproduce some semblance of what I saw in the old days.

That makes sense.  I haven't had to do that, because I started using
assumed_gamma 1 from literally my second day using POV-Ray.  I never had
to make any transition.  But if you're converting old scenes, by all
means use srgb <.7,.8,.9>.

I had been wrestling with gamma long before I downloaded POV-Ray, so I
was onto assumed_gamma in version 3.5, before most POVers realized that
this was an issue.

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