Hello. As the title sais, the gamma slider has no effect. The game is stuck on maximum, so basically there's no darkness. I noticed it got fixed (proper darkness) after some cutscenes in the Khan DLC mission, in the train. I reverted to too bright afterwards. I tried changing the r_gamme value in the .cfg file, but it always resets to 1.something. I also noticed it's a often reported issues, on multiple OSs and hardware configurations. There are multiple subjects on the Steam community forum. Is there a way to fix it? Do any developers read these forums? My specs are: i7 3770k, Radeon HD6850 with git mesa and kernel 3.14rc4, Ubuntu 13.10.
The gamma settings (from game menu) don't work on my Debian Linux setup either and there are other people who have reported the very same issue. Didn't bother changing the r_gamma value cause I had no problem with it (though proposed it to a guy in the game's steam community). Might try it tomorrow and post the results here. BTW some options are located both in a user.cfg file placed in a numerical folder inside of the game's directory in the steam path and another one located in the game's root directory (just outside the numerical one). I think that the one in the root directory has more options (mainly key bindings) in it. Which one does actually work for setting the settings?
