Ive <ive### [at] lilysoftorg> wrote:
> Am 10/28/2020 um 2:03 schrieb Kenneth:
> >
> > Or is   srgb 0.7*<.3,.5,.7>  perfectly OK by itself?
> >
> No it isn't. When using the keyword "srgb" you just tell POV-Ray that
> the following color term is "sRGB gamma encoded".
> Multiplying any non linear color value does not only change the
> brightness but also the hue - and is therefor plain wrong.
>
> ...I'm not sure if
> it will swallow this syntax but at least you should get the idea...
>
> #declare C = (srgb <.3,.5,.7>) * 0.7;

Yes, that's very similar to my rather fuzzy understanding of one of Clipka's
older discussions. I should try that (or similar syntax), and compare it to the
function's use.

Thanks to both you and Bald Eagle for clarifying things. Much appreciated.
>
> ...and BTW I just stumbeled over your bold statement
>
> [quote]
> simply to get the color I 'visually' expect as
> opposed to 'linear' rgb colors that are intrinsically washed-out in an
> assumed_gamma 1.0 environment.
> [/quote]
>
> I used from the very start (more then 2 decades ago, I guess 3.0 at the
> time) assumed_gamma 1.0 (I already had some experience in the field of
> image processing) and no image I ever created suffered from a washed-out
> look. Some early images of mine did look ugly because my own bad choice
> of colors or bad arrangement of objects but these are no gamma related
> problems ;)
>

That was my MAJOR misunderstanding in the old days-- using assumed_gamma 2.2
simply because the rgb colors I chose didn't look like what I expected...Uh,
washed out from using the values that I *thought* were correct. (I was never any
good at trying to 'massage' linear rgb colors to look right in assumed_gamma 1.0
back then; it seemed so counter-intuitive. So assumed_gamma 2.2 seemed like an
'easy fix', ha.) But I had no clue or worry as to how that affected the
lighting; it looked OK to me at the time. Duh. Once srgb colors came along, I
finally had a long-awaited 'eureka' moment about what I had done wrong, and
finally switched to assumed_gamma 1.0. Better late than never! ;-)
>
>
> And BTW-2 your cityscape looks phantastic and things like this are still
> the strength of POV-Ray even when it has sadly fallen far behind as a
> render engine.
>
Thanks! I truly appreciate the comments.

Post a reply to this message