Shade Windows to Eliminate All Extraneous Light
Controlling the effects of ever-changing window light is an essential first step. The goal here is simple: to establish and maintain room lighting at a constant level and white point throughout the day.

If necessary, use flat-black mini-blinds; a dark, neutral-colored decorative valance; and window sills painted a flat black to reduce the amount of light entering the room through each window. Even these steps may not fully resolve the problem, and patches of sunlight may stream through. In a pinch, a fabric sunscreen can be attached to the exterior of some windows to block up to 75 percent of the sunlight entering a room. These tightly woven, wire screens also add privacy and security, since they help keep someone outside from seeing your valuable computer equipment. In worst-case scenarios, you may have to paint window panes a flat black paint or block them with masks such as foil or black matte board.

In many cases, no single idea will work alone and you may have to combine several techniques to sufficiently mask your windows. Unlike a chemical darkroom, the windows in a "digital" darkroom do not have to be blacked out completely, but most of the natural light should be eliminated.

Of course, you should avoid placing your monitor in front of a window unless the window is heavily shaded as indicated above. Otherwise, as you sit facing the window to look at the monitor, you'll constantly have problems both adjusting to the contrast between the monitor and sunlight and judging contrast values in images on the monitor. If the monitor glass is oriented toward the window, reflections will be problematic. Instead, orient the monitor so that the front glass is at a right angle to windows. And of course, shade or mask those windows if at all possible.

Paint Editing-Room Walls a Color-Neutral Light Gray
Experts recommend a color-neutral light gray of about 60-percent reflectance. Latex paint for labs is available from Graphic Technology Inc. of Newburgh, NY. Alternatively, you can have your local paint supplier mix a custom formula to match N8/ gray from the Munsell Books of Color. Paint manufacturers occasionally change formulas, but here are two (compiled in late 2000) to consider.

California photographer Jack Kelly Clark recommends mixing one gallon of Pittsburgh Paint's pastel-tint white base #80-110 with Lamp black (B-12/48 PPG*); Raw Umber (L-36/48 PPG); and Permanent Red (O-3/48 PPG). Write those numbers down and take them with you to the paint store if you want to try the mix yourself.

A similar Kelly-Moore Paint Co. formula from photographer John Palmer uses a pastel-tint white as a base with three colors to create an interior, flat latex similar to Munsell 8 gray: Lamp black (4/48 PPG), Raw Umber (27/48 PPG), Violet (2/48 PPG).

Eliminate Bright Colors from the Room
Get rid of brightly lit (or colored) objects in the field of view directly behind your monitor, particularly if you go to the trouble of painting your walls neutral gray. Some professionals further refrain from wearing brightly lit clothing that could reflect into the monitor.

You should also avoid using brightly colored pictures as your computer desktop background or wallpaper. Use Adobe Photoshop or another image editing program to create a simple gray image file.