Sun's SX hardware does about all you can without going to more than eight bits per channel.. use their command cg14config -g _gammavalue_ to setup a gamma lookup table (in the SX aka cg14 hardware) for the gamma you give, or use cg14config -U _filename_ to load your table with whatever (8-bit) values you want for each of the 256 non-negative integer intensities. Oh, their 3D hardware called ZX (or sometimes called leo), they have the command leoconfig -G _gamma_value_ to setup this hardware with whatever gamma value you want. The leo hardware may not have the ability to load arbitrary correction tables. Note that all this correction works in the display hardware.. no speed cost. Could be that Sun did something right. Why I hear that Sun is even active in some standards for color (and gamma) management software. Sun had some sort of calibration probe on display with an SX workstation at the last Siggraph.Thanks to Carl F. Diegert
You may also want to use the Knoll corrector set to 2.2 if you are producing images for others to view on the Web.
"It's problematic.Sam Merrell
"In several Compuserve libraries, there's a file called MONCAL.GIF which, when viewed with a non-gamma-correcting gif viewer, will give you an idea of your monitor's native gamma.. a place to start. While viewing MONCAL, Brightness and Contrast controls on the monitor can be adjusted, which may or may not get you closer to a 1.8 - 2.2 range.
"Aldus Photostyler and Adobe Photoshop/WIN both include monitor calibration sw routines. You mention Knoll's GAMMA in the MAC discussion and it's included in the PC version (although there's a bug which makes it seem like the utility doesn't work-it does, it just doesn't look like it's storing user settings.. but it does)."
The default system gamma value of 1.7 is stored in /etc/config/system.glGammaVal. You can also set a new gamma value as root using the gamma command: /usr/sbin/gamma [newvalue]. Unless you have a very old SGI, you should not need to restart the X server.
You can calibrate your monitor using the Monitor Confidence Test (part of the sysadmdesktop subsystem), accessible from Toolchest (System > Run Confidence Tests), or via the command line: /usr/sbin/Confidence/monitor -test monitor. This includes focus, raster regulation, grey scale, and convergence; if you're like me, having the owner's manual for the monitor is handy for explaining those icons.
An alternate method is to set gamma at 2.4 and run /usr/sbin/gamcal. Consult the UNIX man page man 6 gamcal for more detailed instructions. After calibration, change the gamma back to 1.7 for regular use.