Glossary 59
Laser Pointer—A small pen or cigar-sized pointer, that contains a small battery
powered laser, which can project a small, red (typically), high intensity beam of
light that is immediately very visible on the screen.
Maximum Distance—The distance from a screen the projector can be to cast an
image that is useable (bright enough) in a fully darkened room.
Maximum Image Size—The largest image a projector can throw in a darkened
room. This is usually limited by focal range of the optics.
Metal Halide Lamp—The type of lamp used in many medium and all high end
portable projectors. These lamps typically have a "half-life" of 1000-2000 hours.
That is they slowly lose intensity (brightness) as they are used, and at the "half-life"
point, they are half as bright as when new. These lamps output a very "hot"
temperature light, similar to mercury vapor lamps used in street lights. Their
whites are extremely white (with a slight bluish cast) and make a halogen lamp's
whites look very yellowish by comparison.
Minimum Distance—The closest position that a projector can focus an image
onto a screen.
NTSC—The United States broadcast standard for video and broadcasting.
PAL—A European and international broadcast standard for video and
broadcasting. Higher resolution than NTSC.
Power Zoom—A zoom lens with the zoom in and out controlled by a motor,
usually adjusted from the projector's control panel and also the remote control.
Reverse Image—Feature that allows you to flip the image horizontally. When
used in a normal forward projection environment text, graphics, etc, are
backwards. Reverse image is used for rear projection.
RGB—Red, Green, Blue — typically used to describe a monitor that requires
separate signals for each of the three colors.
S-Video—A video transmission standard that uses a 4 pin mini-DIN connector to
send video information on two signal wires called luminance (brightness, Y) and
chrominance (color, C). S-Video is also referred to as Y/C.
SECAM—A French and international broadcast standard for video and
broadcasting. Higher resolution than NTSC.
SVGA—Super Video Graphics Array — 800 x 600 pixels count.
SXGA—Super Ultra Graphics Array, — 1280 x 1024 pixels count.
UXGA—Ultra Extended Graphics Array — 1600 x 1200 pixels count.