Thank you for your reply, but I'm sorry; I don't think I was being 
clear. It's not just that the two files **look** different when viewed 
on a Macintosh vs. a Windows display--they ARE different. If I open up 
both files on my gamma-corrected Windows workstation in Paint Shop Pro 8 
and examine the RGB values for pixels at the same location on both 
files, the RGB values on the Mac file are **lower**. The PNG file being 
rendered by POV-Ray 3.6 doesn't just LOOK darker... it IS darker.

Thorsten Froehlich wrote:
> You need to enable gamma correction for your PC.  By default PC settings
> display extremely bright images on screen.  This is the case for all
> programs, not just POV-Ray.  You need to understand that the display gamma
> setting is exactly there for this purpose, and setting it to the same value
> on two systems with a different display gamma cannot possibly work.  You
> need to set it to the true gamma of each system, not the same on both!

I'm sorry, I must be misunderstanding you. Surely you are not saying 
that it is impossible to get a scene file to render exactly the same on 
Macintosh and Windows?

I don't give a fig that the Macintosh gamma is different from the 
Windows workstation--I do all my POV-Ray development on the Windows 
machine and the brightness for my scene has been set for the gamma on 
that machine. All that I want to do is fool the Macintosh into rendering 
the scene file so that it produces **exactly** the same resulting PNG 
file that I would get on the Windows machine. From reading the help file 
on Windows, it would seem that if I set assumed_gamma to 1.0, POV-Ray 
uses the Display_Gamma value that's stored in povray.ini (or 
<scenefilename>.ini on Macintosh). If the Display_Gamma is the same on 
both workstations, shouldn't I get exactly the same file on both 
workstations, or is this not possible with POV-Ray for Mac 3.6?

Thank you.

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