Jonathan Rafael Ghiglia wrote in message
<3a44ba2d.1127967@news.povray.org>...
>I don't know how to properly set the assume and display gamma. After a
>test with the "monitor gamma adjustment" of Paint Shop Pro I know my
>monitor's gamma should be 1.21,

Are you sure of this?  It seems a little low as gammas go.  I know different
programs have different ideas of what "gamma" is.  You might try
double-checking using the "gamma.gif" file.  The file and instructions for
using it can be found at the bottom of
http://www.povray.org/binaries/index.html

>but if I set both the assume gamma in
>the global settings and the display gamma in the INI file to 1.21 I
>get my images too dark (the same thing happens if I set both to 2.2,
>for example). If I set the assume gamma to 1.21 and leave the display
>gamma to 2.2 (the default value) I get my images too bright. How
>should I set the two values?

You should set the display gamma to the gamma value of your monitor.  For
most purposes, you should set the assume_gamma to 1.0.

>What is more, some of my PNG images seem
>to look really too dark with some viewers, while with most viewers
>they look right. Is it due to the image file gamma stored in PNG
>files?

Yes.  This can also cause problems with using PNG images, if the program
that created the PNG image set the gamma information to 1.0, rather than the
gamma of the monitor being used.  In this case, you may need to fiddle
around with the "assumed_gamma" value in your scene.

--
Mark

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Jonathan Rafael Ghiglia wrote:
> 
> I don't know how to properly set the assume and display gamma. After a
> test with the "monitor gamma adjustment" of Paint Shop Pro I know my
> monitor's gamma should be 1.21, but if I set both the assume gamma in
> the global settings and the display gamma in the INI file to 1.21 I
> get my images too dark (the same thing happens if I set both to 2.2,
> for example). If I set the assume gamma to 1.21 and leave the display
> gamma to 2.2 (the default value) I get my images too bright. How
> should I set the two values? What is more, some of my PNG images seem
> to look really too dark with some viewers, while with most viewers
> they look right. Is it due to the image file gamma stored in PNG
> files?

	I have not read the other responses before I post this. 

	My answer is there is no right answer. 

	That is one of the reasons why Gimp and Photoshop and similar are
permitted to change things within reasonable limits. 

	It takes a bit of practice to make everything work together but they
do. 

-- 
He who casts a vote decides nothing. 
He who counts the votes decides everything. 
First said by Joe Stalin, then by Al Gore. 
	-- The Iron Webmaster, 210

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