Celestia Forums

The visibility of certain delicate features, like galaxy rendering etc, is crucially dependent on the appropriate global monitor brightness/contrast settings. Brightness may be required so high that other applications appear uncomfortably bright.

I would thus appreciate the possibility of setting a "gamma" factor locally in celestia.

Fridger

Indeed. Gamma correction would make things appear much more real in Celestia. I've found on the Internet a very good page explaining what is gamma correction and how to use it.
I did some tests of my own, and I found out that the system gamma correction factor that should be used for Windows is roughly 2 (I'll post a more accurate value, if I'm able to make another test).

http://www.cgsd.com/papers/gamma_intro.html

Gamma correction is great, because it allows to accomodate a very large range of brightness in the relative narrow range of levels available for each colour (0-255). For example, it allows us to render Pluto and Earth with their actual brightness. If we render the brightest features on Earth with the color (0xFF,0xFF,0xFF) (white, maximum brightness), the brigthest features on Pluto (albedo=100% and assuming Pluto receiving about 1/1000 light per square meter as Earth does) should be rendered with the color (0x08,0x08,0x08) for a system gamma of 2. ( 8 = 255 * (0.001)^(1/2) )

I'm not sure, but it seems that Celestia 1.3.1 doesn't take into account gamma correction. Chris, pardon me if I'm wrong.

Cheers,
Marcio.