Editing Digital light processing (section)

==== Color wheel "rainbow effect" ====
[[File:DLP rainbow effect.JPG|thumb|left|The rainbow effect found in 1DLP projectors only utilizing a mechanical spinning wheel]]Single-chip DLP projectors utilizing a mechanical spinning color wheel may exhibit an anomaly known as the "rainbow effect". This is best described as brief flashes of perceived red, blue, and green "shadows" observed most often when the projected content features high contrast areas of moving bright or white objects on a mostly dark or black background. Common examples are the scrolling end credits of many movies, and also animations with moving objects surrounded by a thick black outline. Brief visible separation of the colors can also be apparent when the viewer's gaze is moved quickly across the projected image. Some people perceive these rainbow artifacts frequently, while others may never see them at all.

This effect is caused by the way the eye follows a moving object on the projection. When an object on the screen moves, the eye follows the object with a constant motion, but the projector displays each alternating color of the frame at the same location for the duration of the whole frame. So, while the eye is moving, it sees a frame of a specific color (red, for example). Then, when the next color is displayed (green, for example), although it gets displayed at the same location overlapping the previous color, the eye has moved toward the object's next frame target.  Thus, the eye sees that specific frame color slightly shifted. Then, the third color gets displayed (blue, for example), and the eye sees that frame's color slightly shifted again.  This effect is not perceived only for the moving object, but the whole picture. Multi-color LED-based and laser-based single-chip projectors are able to eliminate the spinning wheel and minimize the rainbow effect since the pulse rates of LEDs and lasers are not limited by physical motion. Three-chip DLP projectors function without color wheels, and therefore do not manifest this rainbow artifact."<ref>The Great Technology War: LCD vs. DLP. By Evan Powell, December 7, 2005. Accessed online at: http://www.projectorcentral.com/lcd_dlp_update7.htm?page=Rainbow-Artifacts. Accessed on Dec. 27, 2011.</ref>