12.1.1.3.1-9 Luminance Ratio for Projected Displays
The luminance ratio provided by the projection system should be adequate for the type of material being projected.
Additional Information: The contrast ratio is defined as image or subject luminance divided by the nonimage or background luminance. Under optimal ambient lighting conditions, the contrast ratio for optically projected displays should be 500:1. Minimum contrast ratios are as follows:
- For viewing charts, printed text, and other linework using slides or opaque projectors, the minimum contrast ratio is 5:1.
- For projections that are limited in shadows and detail, such as animation and photographs with limited luminance range, the minimum contrast ratio is 25:1.
- For images that show a full range of colors (or grays in black-and-white photographs), the minimum contrast ratio is 100:1. 5908