127 said:
Matching the visual colour of a safelight aint gonna work - You need to think of the spectra...
A light bulb puts out a near continuous spectra while a monitor is made up of three seperate light sources. The results might look the same to the human eye but they're very different. To get something which looks like the orange/red of (some) safelights you might be putting out a lot of green to trick the eye into seeing orange (whereas REAL orange may contain little green).
The red gun is (probably) putting out the least energy in the bands that are affacting orthochromatic materials, so I'd set up a colour scheme which just uses shades of read (or cut the wires in the monitor lead for green and blue). After that it's just a question of intensity - adjust the brightness and do a safelight test.
Ian
I'd agree that you don't want any green or blue content, but the programs you run would have to take that into account and run in a monochrome red scheme, or perhaps monochrome B&W with the blue and green channels off.
I work in an observatory, and a coworker bent the red pin on our monitor cable plugging it in in the dark. That gave us a monitor with no red signal, which is the inverse of what we need in an observatory. This brings to mind a possible solution for any color monitor without permanently cutting wires. Make a short extension cable to go on the monitor cable, but leave off the blue and green connections, or put an inline switch to toggle them on/off as needed. Standard pinouts for monitor cables should be easy to find on the internet.
You'll still need to adopt a color scheme that's readable, and keep the maximum brightness on any given screen display that you use below fogging levels.
In Xwindows under linux, you could try:
xgamma -ggamma 0.1 -bgamma 0.1
at the command prompt. You can't go below 0.1 on the gamma, and the screen runs from black through red to white, so you'd still need a red filter over the screen to knock down the full spectrum highlights.
Lee