Definition: Contrast ratio is the difference between the brightest whites and the blackest blacks that a television or video projector can display. High contrast ratios deliver whiter whites and blacker blacks and a greater degree of gray values in between. If the contrast ratio is low, even if the image is bright, your image will look washed out. Beware of outrageous contrast ratio numbers based on "Dynamic" or "On/Off" numbers. Look for contrast ratio numbers that refer to "Native" or "ANSI" numbers. For a good perspective on the nature of contrast ratios, check out the articles: What is Contrast Ratio (About.com TV/Video) and The Contrast Ratio Game (Practical Home Theater Guide.com).