Glossary 79
room. This is usually limited by focal range of the optics.
Minimum Distance — The closest position that a projector can focus an image
onto a screen.
NTSC — National Television Standards Committee. North American standard for
video and broadcasting, with a video format of 525 lines at 30 frames per second.
PAL — Phase Alternating Line. A European broadcast standard for video and
broadcasting, with a video format of 625 lines at 25 frames per second.
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, closely related to PAL but with a different method of sending color
information.
SVGA — Super Video Graphics Array — 800 x 600 pixels count.
SXGA — Super Extended Graphics Array, — 1280 x 1024 pixels count.
UXGA — Ultra Extended Graphics Array — 1600 x 1200 pixels count.
VGA — Video Graphics Array — 640 x 480 pixels count.
XGA — Extended Video Graphics Array — 1024 x 768 pixels count.
WXGA — Wide Extended Graphics Array — 1280x800 pixels count.
Zoom Lens — Lens with a variable focal length that allows operator to move the
view in or out making the image smaller or larger.
Zoom Lens Ratio — Is the ratio between the smallest and largest image a lens can
projector from a fixed distance. For example, a 1.4:1 zoom lens ratio means that a
10 foot image without zoom would be a 14 foot image with full zoom.