Monitor Viewing Conditions

David Q. McDowell, Senior Technical Associate, Eastman Kodak Company

Until now, the industry has not had any recommended conditions for viewing images on a monitor. This was not a problem as long as people were not trying to make final judgments based on a soft display. But as the digital workflow matures, this issue takes on new importance. The new version of ISO 3664-Viewing Conditions for Graphic Technology and Photography contains specifications for the viewing of a monitor independent of any form of hard copy. Thus, these specifications can be seen as primarily relevant where successive viewing of hard copy and soft copy takes place. They include the following requirements:

• The chromaticity of the white displayed on the monitor should approximate that of D_65. The luminance level of the white displayed on the monitor shall be greater than 75 cd/m² and should be greater than 100 cd/m². (When a standard says "shall", the requirement must be met; "should" is a strong recommendation).
• When measured in any plane around the monitor or observer, the level of ambient illumination shall be less than 64 lux and should be less than 32 lux. The color temperature of the ambient illumination shall be less than or equal to that of the monitor white point.
• The area immediately surrounding the displayed image shall be neutral, preferably grey or black to minimize flare, and of approximately the same chromaticity as the white point of the monitor.
• The monitor shall be situated so there are no strongly colored areas (including clothing) directly in the field of view or which may cause reflections in the monitor screen. Ideally, all walls, floors, and furniture in the field of view should be grey and free of any posters, notices, pictures, wording or any other object that may affect the viewer's vision.
• All sources of glare should be avoided since they significantly degrade the quality of the image. The monitor shall be situated so that no illumination sources such as unshielded lamps or windows are directly in the field of view or are causing reflections from the surface of the monitor.

These are clearly things that are seldom done today. Having clearly specified goals, however, should allow us to move one more step forward in the communication of the appearance of color images on a monitor.

Note: 64 lux = 100 watt frosted light bulb at a distance of ~48" and 32 lux =~78"