Appendix: Glossary
ANSI LUMENS
ASPECT RATIO
Brightness— The amount of light emitting from a display or projection display or projection device. The brightness of projector is measured by ANSI lumens.
Color Temperature— The color appearance of white light. Low color temperature implies warmer (more yellow/red) light while high color temperature implies a colder (more blue) light. The standard unit for color temperature is Kelvin (K).
Component
Composite Video — A video signal that combines the luma (brightness), chroma (color), burst (color reference), and sync (horizontal and vertical synchronizing signals) into a signal waveform carried on a single wire pair. There are three kind of formats, namely, NTSC, PAL and SECAM.
Compressed Resolution— If the input images are of higher resolution than the native resolution of the projector, the resulting image will be scaled to fit the native resolution of the projector. The nature of compression in a digital device means that some image content is lost.
Contrast Ratio— Range of light and dark values in a picture, or the ratio between their maximum and minimum values. There are two methods used by the projection industry to measure the ratio:
1 Full On/Off — measures the ratio of the light output of an all white image (full on) and the light output of an all black (full off) image.
2 ANSI — measures a pattern of 16 alternating black and white rectangles. The average light output from the white rectangles is divided by the average light output of the black rectangles to determine the ANSI contrast ratio.
Full On/Off contrast is always a larger number than ANSI contrast for the same projector.
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