Product guide
Vertical Lens Shift The purpose of Lens Shift is to
eliminate keystoning and provide greater exibility in the
placement of the projector relative to the screen. Lens
shift may be a manual adjustment or motorized depend-
ing on the projector. Vertical lens shift will typically allow
the projector to be placed anywhere between 1.5 screen
heights above or below the center of the projection screen
and may also be used to geometrically align images when
stacking projectors. Horizontal lens shift is also available on
some projectors.
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.
VESA (Video Electronics Video Association). An interna-
tional non-prot corporation led by a board of directors,
which represents a voting membership of more than 165
corporate members worldwide. VESA supports and sets
industry-wide interface standards for the PC, workstation
and consumer electronics industries. The VESA mounting
interface standard includes a pattern of mounting holes on
the back of a at-panel display which match up with pat-
terns found on many at-panel mounts. Mounting patterns
are measured in millimeters and most common patterns
are 75 x 75mm, 100 x 100mm, 200 x 100mm and 200 x
200mm. Mounting patterns beyond those listed have varied
sizes and are spaced in 200mm increments.
VGA A display resolution measuring 640 horizontal pixels
and 480 vertical pixels giving a total display resolution of
307,200 individual pixels. VGA has a 4:3 aspect ratio.
Video Bridge A computerized switching system, or
MCU, which allows multipoint video conferencing.
Video Capture The method of capturing an analogue
video source and converting it into a digital format.
Video Conferencing A form of communication in which
a set of interactive telecommunication technologies allow
two or more locations to interact via two-way video and
audio transmissions simultaneously.
Video Mirroring An output connector on the projector
that allows a monitor or another projector to share the same
video source.
Video Wall Consists of multiple displays or monitors that
are mounted closely together contiguously in order to form
one large screen.
Viewing Angle Screens do not reect equally in all di-
rections. Most light is reected in a conical volume centered
around the “line of best viewing”. Maximum brightness is
perceived if you are within the viewing cone dened by the
horizontal and vertical viewing angles.
VoD Server (Video on Demand). Refers to any streaming
video server that can store and deliver video streams on
request from end users.
Voice-Activated Switching (VAS) Usually the default
mode in multiple sites where the personal currently speak-
ing can be viewed by all participants. Noise in a site will
cause the view to change.
Volt A measurement of electrical pressure.
Volume Leveling The automatic increasing or decreas-
ing of volume during playback to produce a similar sound
for all audio content.
VPN (Virtual Private Network). A service offered by public
carriers whereby the user is given a network that appears
to be private but which is actually carried over a public
network.
VSAT (Very Small Aperture Terminal) VSATs are those little
satellite dishes that you see used for PrimeStar and DirecTV
among other things. In addition to tuning in satellite TV, they
can be used to receive data such as IP multicasting. Many
companies create a wide area computer networks (WAN)
infrastructure.
W
WAN (Wide Area Network). A communications
network that uses devices such as telephone
lines, satellite dishes, or radio waves to span a
larger geographic area than can be covered by a LAN.
Watt A unit of power. Volts multiplied by amperage equals
watts. It is dened as one joule per second.
WAV This is a format for a digital audio sound le.
Web Server A server that stores and retrieves HTML
document and other resources using HTTP.
Webcast The delivery of a live or recorded broadcast
over the web.
Wedge Anchor Wedge anchors, also known as expan-
sion bolts and expansion anchors, secure themselves using
a mechanical wedging effect at the end of the fastener.
Tightening the bolt results in a wedge being driven up
against a sleeve. This jams the end of the bolt and provides
the strength. Many different manufacturers provide a varia-
tion on this theme, usually depending on the condition of
the concrete and the type of load.
Weight Capacity The maximum amount of weight that
a mount can support. All of our mounts are tested at a
minimum of four times the weight of the advertised weight
capacity to ensure stability and safety.
White Level The signal level that corresponds to the
maximum picture brightness. The white level is set by the
contrast control.
Widescreen Any aspect ratio that is wider than 4:3.
Widescreen televisions are 16 units wide and 9 units tall.
Common widescreen lm aspect ratios are 1.66:1, 1.85:1
and 2:35:1.
Wi-Fi (802.11a) An IEEE specication for wireless net-
working that operates in the 5 GHz frequency range (5.725
GHz to 5.850 GHz) with a maximum 54 Mbps data transfer
rate. The 5 GHz frequency band is not as crowded as the
2.4 GHz frequency, because the 802.11a specication offers
more radio channels than the 802.11b. These additional
channels can help avoid radio and microwave interference.
Wi-Fi (802.11b) International standard for wireless net-
working that operates in the 2.4 GHz frequency range (2.4
GHz to 2.4835 GHz) and provides a throughput of up to 11
Mbps. This is a very commonly used frequency. Microwave
ovens, cordless phones, medical and scientic equipment,
as well as Bluetooth devices, all work within the 2.4 GHz
frequency band.
Wi-Fi Wireless Fidelity, and is a type of wireless network
used to connect digital devices without the need for cables.
It is mostly used for wireless broadband access and
inexpensive consumer wireless antennas are available at
electronics stores. There are four specications currently in
th e famil y : 8 0 2.11, 802.11a, 8 0 2.11b, a nd 8 0 2.11g.
Wire Gauge A measurement of how large a wire is, either
in diameter or cross sectional area. This determines the
amount of electric current a wire can safely carry, as well as
its electrical resistance and weight per unit of length. Wire
gauge is applicable to both electrical and non-electrical,
structural wires.
Woofer A loudspeaker designed to reproduce bass, or
low audio, frequencies.
WXGA (Wide Extended Graphics Array). Denes a class
of XGA displays with a width resolution sufcient to create
an aspect ratio of 16:9. A WXGA display has 1366 to 1280
pixels horizontally and 768 to 720 pixels vertically.
X
XGA (Extended Graphics Array). Display
resolution measuring 1024 pixels horizontally and
768 pixels vertically giving a total display resolution
of 786,432 individual pixels. XGA has a 4:3 aspect ratio.
XLR Balanced connection for audio components and
used professionally.
XML (Extensible Markup Language) XML is a standard
data format used for text les and information in computer
memory that allows easy data processing and exchange
between different applications.
XSL (Extensible Stylesheet Language) XSL was the origi-
nal proposal to allow formatting of XML les for display. It
has since diverged into XSL FO and XSLT. They each derive
from XSL, but use different parser programs and achieve
slightly different goals. XSL FO, which stands for XSL
formatting objects, is most often used for outputting PDF
les with extreme formatting and pagination control. XSLT,
which stands for XSL transformations, is most often used to
convert one XML data structure into another.
XSLT (Extensible Stylesheet Language Transformations)
XSLT is a standard subset language of XML designed to
allow one XM.
Y
Yaw Taken from the aviation industry, the yaw
refers to the rotation around the axis that will move
the image on a screen left or right, while pitch
refers to the axis of rotation that would move the image of a
projector up and down on a screen. Roll refers to the axis of
rotation that would rotate the image of a projector on a
screen.
Y-Splitter A cable or adapter that enables a single out-
put into two inputs or a single input into two outputs.
Z
Zipcord Cable A at cable looking like two
cables glued together commonly used for audio
applications.
Zoom Lens A lens with a variable focal length providing
the ability to adjust the size of a projected image without
moving the projector or provide a range of projector place-
ments that can produce the same size image. See Zoom
Ratio.
Zoom Ratio Zoom ratio is the ratio between the smallest
and largest image a lens can projector from a xed dis-
tance. 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. Conversely, a 10 foot diagonal image at 15 feet with
no zoom would still be a 10 image at 21 feet at maximum
zoom (15 x 1.4 = 21 feet). A zoom lens is “not as bright” as a
xed lens, and the higher the ratio, the less light output.
PRO AV GLOSSARY
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