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SECAM
➤
A video output format of some video tape and disk players (used primarily in France).
SECAM (Sequential Couleur á Mémoire) signals are similar in resolution and frequency
to PAL signals. The primary difference between the two standards is in the way color
information is encoded.
Slidebar
➤
A slidebar is a graphical display of an adjustable setting. The numerical setting often
represents a percentage but can be a specific unit such as degrees Kelvin.
Source
➤
The device, such as a computer or VCR, connected to the projector for display. A source
may have numerous corresponding channels defined and recognized by the projector. See
Input.
Source Setup
➤
See Channel.
Switcher
➤
A signal selector that can be connected to a projector for the purpose of adding more
sources.
Sync
➤
This term refers to the part of the video signal that is used to stabilize the picture. Sync can
occur in three forms:
1)
“Composite sync”: the horizontal and vertical components are together on one cable.
2)
“Sync-on-green”: the sync is part of the green video.
3)
“Separate sync” or “H.SYNC and V.SYNC”: the horizontal and vertical components of
the sync are on two separate cables.
Sync Width
➤
The duration of each sync pulse generated by a computer. The sync width is part of the
blanking time.
TTL Video
➤
A type of RGB video with digital characteristics.
Terminated
➤
A wire connecting a single video source to a display device, such as a projector, must be
terminated by a resistance (usually 75
Ω
for video).
Throw Distance
➤
The distance between the projector’s lens and the screen. Also called “Projector-to-Screen
Distance”. Always use the correct Runco throw distance formula to calculate the proper
throw distance required for your lens.
Throw Ratio
➤
Throw ratio = throw distance / screen width. Typically used to differentiate lenses.
Tint
➤
Balance of red-to-green necessary for realistic representation of NTSC signals.
Variable Scan
➤
The ability of a projector to synchronize to inputs with frequencies within a specified range.
Vertical Frequency
➤
The frequency at which images are generated. Vertical frequencies vary amongst sources.
Also called vertical scan rate.
Vertical Offset
➤
The difference between the center of the projected image and the center of the projector
lens. For clarity, offset is often expressed as the maximum amount of the image that can
be projected above or below the lens center without degrading the image quality. Vertical
offset ranges depend on the type of lens in use, and whether or not the image is offset
horizontally at the same time.
Video
➤
The signal that is used by display devices (such as projectors) to generate an image. This
term also refers to the output of video tape/disk players and computers.
Video Decoder
➤
An optional device that converts NTSC 3.58, NTSC 4.4, PAL, PAL-N, PAL-M or SECAM to
RGB video.
Video Standard
➤
A specific type of video signal, such as NTSC, PAL, SECAM. This projector can
automatically recognize and interpret the incoming standard and display accordingly.
Viewing Angle
➤
Screens do not reflect equally in all directions. Most light is reflected in a conical volume
centered around the “line of best viewing”. Maximum brightness is perceived if you are
within the viewing cone defined by the horizontal and vertical viewing angles.
White Balance
➤
The color temperature of white used by the projector.
Appendix A: Glossary
Appendix A: Glossary