Product guide
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1080p ATSC high-denition 1920 x 1080
progressive scan video format where a complete
frame of video is delivered at either 60 or 24
frames per second.
15 Pin D-Sub A connector for a PC’s VGA port or
analogue monitor.
16:9 Aspect ratio of an HDTV signal which is 16 units by
9 units, whatever size those units may be. In the lm trade
aspect ratios are described in relation to one, which means
this aspect ratio is described as 16/9 or 1.78:1.
2.2 Pull-Down This refers to the electronics required to
convert lm footage to PAL and SECAM video format.
2:2 Pull-Down Method for transferring 24 frame-per-
second lm to PAL/SECAM video running at 25 frames per
second.
2:3 Pull-Down Commonly called 3:2 pull-down,
converts lm footage to NTSC video. Film footage is shot
at 24 frames per second (FPS) and NTSC video is shot at
30 FPS. 3:2 pull-down refers to the electronics needed to
convert 24 FPS to 30 FPS so that it can be viewed on a
NTSC video device. To accomplish this, 4 frames of lm are
converted to 5 frames of video by inserting an extra eld of
lm frame every other frame.
3:2 Pull Down Method used to map the 24 FPS of lm
onto the 30fps (60 elds) of 525 line NTSC video, so that
one lm frame occupies three video elds, the next two,
etc. In this way the lm can play at a standard video rate. It
means the two elds of every other video frame come from
different lm frames, this can cause problems in the editing
process.
3D Ready A projector that is 3D Ready can accept a
120Hz frame-sequential 3D signal from a computer via
either NVIDIA’s 3D Vision system or one of several educa-
tional software suites. These projectors are not compatible
with the HDMI 1.4 3D specication used on 3D Blu-ray
players and set-top boxes. We also refer to this type of 3D
as PC 3D Ready.
3LCD Common 3 color system for projecting images
via LCD or Liquid Crystal Display. Uses dichroic mirrors to
separate the RGB components of white light coming from
a projection lamp. Each color is fed to separate LCD panels
which controls the amount of colored light that passes
through. The light from each LCD is recombined using a
dichroic prism before going out the lens and onto a screen.
4:1:1 Sampling A ratio used to describe the sampling
frequency of a digitized signal. The ratio describes lumi-
nance as being sampled 4 times at 3.37 MHz, while color
is sampled 1 time at 3.37 MHz in each of its separate parts.
DV, DVCAM and DVCPRO25 use 4:1:1 color sampling. For-
mulated as:Y (luminance) is sampled at 13.5 MHz (or 3.37
x 4), R-Y (color) is sampled at 3.37 MHz (or 3.37 x 1), B-Y
(color) is sampled at 3.37 MHz (or 3.37 x 1) equals 4:1:1.
4:3/16:9 Dual Format This dual format enables the
viewer to switch between alternative picture formats in
traditional square or wide-screen views.
480i ATSC Standard Denition Television (SDTV) 720 x
480 or 640 x 480 interlaced video format where a frame of
video is delivered in two elds. The rst eld contains the
odd lines of the image and the second eld contains the
even lines. Each eld is updated every 1/60th of a second
resulting in 30 frames of video per second.
480p ATSC Enhanced Denition Television (EDTV) 720 x
480 progressive scan video format where a complete frame
of video is delivered at either 30 or 24 frames per second.
480p also refers to a display format comprised of 854 x 480
pixels, 16:9 widescreen.
720p ATSC high denition 1280 x 720 progressive scan
video format where a complete frame of video is delivered
at either 60, 30 or 24 frames per second.
A
Aliasing During the quantization or re-quantiza-
tion process, unnecessary artifacts may be
generated due to interpolation (a method for
generating inter-sample data using compulation). This
phenomenon is called “aliasing”, and the distortion it causes
is called “aliasing distortion” or “fold-back noise”. Aliasing
distortion can cause smear or icker on the image.
ALIS Alternate Lighting of Surfaces is a method of achiev-
ing high denition and high brightness.
Ambient Light The light of lighting present in a room
other than the light emitted by a projector.
Analogue These signals are the traditional format in
which audio and video are transmitted. A digital signal will
usually produce a superior video quality.
Anamorphic A technique for changing aspect ratios by
optically or digitally stretching or compressing an image to
or from a format with a different native aspect ratio. Movie
studios used this technique to put the rst widescreen mov-
ies on standard 35mm lm and then used an anamorphic
lens to recreate the image in the widescreen format in which
it was originally shot.
AnimGIF An animation in the GIF format, capable of auto-
matic looping playback. See also GIF.
ANSI Contrast The ratio between white and black. The
larger the contrast ratio the greater the ability of a projector
to show subtle color details and tolerate extraneous room
light. There are two methods used by the projection indus-
try: 1) Full On/Off contrast 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 contrast is measured
with 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. When comparing the
contrast ratio of projectors make sure you are comparing
the same type of contrast. Full On/Off contrast will always
be a larger number than ANSI contrast for the same projec-
tor.
ANSI Lumens ANSI lumens is a measurement of the
overall brightness of a projector. Because the center of a
projected image is brighter than the corners, ANSI lumens
are the most accurate representation of the image bright-
ness. ANSI lumens are calculated by dividing a square
meter image into 9 equal rectangles, measuring the lux (or
brightness) reading at the center of each rectangle, and
averaging these nine points.
ANSI American National Standards Institute. A private
organization that coordinates and administers various vol-
untary consensus standards such as ANSI lumens. The rst
ANSI standard was for pipe threading in 1919 when it was
called the American Engineering Standards Committee.
API Application Programming Interface is the format
used by an application to communicate with an operating
system.
Artifacts Flaws and aberrations in a video image that
derive from technical limitations in the capture, encoding/
decoding, transmission, and display of a video signal.
ASCII (American Standard Code for Information Inter-
change) The universal standard for representing text letters,
numerals, punctuation marks and control instructions in
computer storage and communication.
Aspect Ratio The ratio of height over width of an image:
a standard video monitor has an aspect ratio of three units
of height (vertical) to four units of width (horizontal). This is
expressed as a 3:4 aspect ratio. Can also be expressed
as a decimal number, such as 1.77, 1.85 or 2.39. Images
will become distorted if forced into a different aspect ratio
during enlargement, reduction, or transfer. The aspect ratio
for HDTV is 16:9.
ATSC (Advanced Television Systems Committee). Formed
in 1982, this international committee develops voluntary
standards for terrestrial digital television. Countries adhering
to its standards include Canada, Argentina, Mexico, South
Korea and the U.S.A. ATSC Digital TV Standards include
HDTV, SDTV, data broadcasting, multichannel surround
audio, and interactive television.
Audio In-and-Out Connections for external ampliers
and speakers to allow sound output.
Authoring Tools Authoring tools usually refers to
computer software that helps multimedia developers create
products. Authoring tools are different from computer pro-
gramming languages in that they are supposed to reduce
the amount of programming expertise required in order to
be productive. Some authoring tools use visual symbols
and icons in owcharts to make programming easier. Oth-
ers use a slide show environment.
Auto Balance A system for detecting errors in color bal-
ance in white and black areas of the picture and automati-
cally adjusting the white and black levels of both the red and
blue signals as needed for correction.
Azimuth The direction to point a satellite dish when
coupled with altitude. Due north has an azimuth of 0 de-
grees and due east, 90 degrees, and so on.
B
Bandwidth The number of cycles per second
(Hertz) expressed as the difference between the
lower and upper limits of a frequency band; also,
the width of a band of frequencies. Practically speaking,
bandwidth is the amount of data that can pass through a
given connection per unit of time.
Bezel The frame or face of a device, such as, a projector
grill, or CRT or LCD display frame.
Black Level The darkest part of a picture. This can vary
between display devices and viewing environments. NTSC
black is set at 7.5 IRE, which is very slightly gray. The white
level divided by the black level gives a contrast ratio for a
particular display device.
Blackboard Mode Blackboard mode gives the projec-
tor the ability to detect the color of a display surface such as
a chalkboard or painted wall and adjust its output to opti-
mize accurate color reproduction, contributing to increased
comprehension and retention.
Bleeding Video distortion where color “bleeds” from an
object onto other parts of the image which are not sup-
posed to be that color.
Blooming Video distortion where an overly bright screen
object causes phosphors near it to excite, therefore enlarg-
ing the object and softening its edges.
Bounding box The box, represented by the selec-
tion frame, that surrounds a multi-line text element. The
element’s text lines can be aligned within the bounding
box (left/center/right) independently of the alignment of the
element as a whole.
Bowing Video distortion where lines which should be
straight are curved. See barrel distortion and pincushioning.
Brightness (Perceived) The brightness of a projection
system can be precisely measured with a light meter. For
example, a typical movie theater is setup to deliver 16’
lamberts. The higher the foot-Lamberts, the brighter the
image. A common misconception is that a projector with
twice the foot-Lamberts of another projector will be twice
as bright. While it is true that a light meter will detect it as
twice as bright, your eye will not. The perceived brightness
will increase by about 50%. It will not double because the
human eye has a logarithmic respond to light.
PRO AV GLOSSARY
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