CCI Audio Visual Design

Definition of Terms
A

Active Matrix TFT

A very common type of LCD, used in most laptops, and some LCD panels and projectors. A typical active matrix TFT display is a single LCD (Liquid Crystal Display) that modulates all three primary colors. Most of these offer contrast ratios up to 100 :1 for good color dynamics, and just enough "speed" to handle video and 30 fps multimedia with little or barely distinguishable picture smear or lag.

Aliasing

Jagged edges in text and also along the outer boundaries of diagonal or curved objects. Anti-alaising refers to software compensation that minimize this effect.

American National Standards Institute (ANSI)

Sets standards for measurements ANSI Lumens, when measured using ANSI methods.

Amplifier

A device used to increase the electrical output of a video or audio signal.

Analog

A way of sending voice, video, or data that is "analogous" to the original signal. Analog transmission is associated with voice and data signals over conventional telephone lines. Contrasting with digital, analog signals have voltage directly analogous to the strength of the corresponding physical signal. That is, the loudness of a sound or the brightness of a light source. The voltage of a signal alternates between positive and negative at the frequency of the sound or light.

ANSI Lumens

ANSI lumens is a scale to measure the overall brightness value for projectors. The measurement represents the average value of 9 points on the projected screen image.

Aspect Ratio

The ratio of height to width of a frame or screen. The aspect ratio for television is 3:4.

ATA Rated Transport Case

A case rated strong enough to be shipped as freight by common carrier such as FedEx or UPS, etc. Most cases of this type are easily recognized by their aluminum outer shell and metal reinforced corners. Many newer cases are made using lightweight corrugated plastics and weigh much less than the aluminum clad cases.

Audio Cable

Cable used to connect from the Audio out on your computer into the Audio in of a projector.

Audio In (Stereo Input)

The jack or jacks (typically standard RCA jacks) to plug in sound coming from an external source such as a VCR or computer. Many projectors have more than one set of inputs, making it easy to switch between sources.

Audio Out (Stereo Out)

The jack or jacks to hook up external amplifier system. Most projectors allow their remote to control the volume of their internal speaker and the external systems.

B
Backlit Display

Refers to a projector control panel, which has buttons that are illuminated. This feature makes it much easier to find the controls when using the projector in a low light environment. Many projectors have feature backlit remote controls.

Back Room Projector

A projector equipped with a "long-throw" lens designed to be used much further away from the screen, often in a projection booth or back of an auditorium. Most projectors have third party lenses available for "long-throw" applications.

Bandwidth

The capacity of any single channel of the system to transmit data.

Baud

The unit of speed that describes the rate at which binary data is transmitted. One baud is approximately equal to one bit per second.

Bit Map File (BMP)

A windows raster graphics format that is an independent of device and is coded for translation to a wide variety of displays and printers. A common file extension is "BMP."

Bit-Mapped Graphics

A form of graphics that are defined and addressed on a bit by bit basis, thereby making all points on the screen display directly accessible.

BNC

Bayonet connector, type of video connection that is connected with a twist lock.

Brightness

A manual adjustment of how bright an image appears through a projection unit.

Cable

Wires and cords used to power and link various pieces of equipment.

Cable Wizard

Cable used to plug in all input devices specific to InFocus projectors.

Carry-on Case

Refers to a projector carry case that is small enough to meet airline standards for carry-on luggage This type of case usually does not have sufficient strength or padding for use as checked luggage.

Cathode Ray Tube (CRT)

A three tube projector with high performance, usually used in large conference rooms.

CD-ROM

Compact disc - read only memory. A CD-ROM looks virtually the same as an audio CD. CD-ROMs can hold up to 650 megabytes of information.

Ceiling Mount

The ability to mount a projector to the ceiling. Most projectors, when ceiling mounted, must be hung upside- down. To eliminate image distortion known as "keystoning", ceiling mountable projectors have the ability to electronically invert the image.

Ceiling Mount Projection

Inverts the image so that the projector may be mounted upside down on the ceiling.

Coated Optics

A process used to modify and improve the optical characteristics of lenses. One of the primary advantages of coating a lens is to minimize the amount of light reflected back to the lamp, and the amount of ambient light that mingles with the focused light leaving the lens. Coatings can improve lens brightness by 15% or more. Coatings can also be used for filtering colors.

Coder/Decoder (CODEC)

An electronic circuit that converts analog signals into digital signals and digital signals into analog signals.

Color Contrast

Refers to the values relationship of the colors used in conjunction within an image. Contrast is required for readability of text, charts and graphs - the more contrast the better the readability.

Color Dynamics

High color dynamics are a result of dynamic range/contrast ratio's. When we describe a unit as having excellent color dynamics, the practical description might be "rich colors, excellent definition, high contrast".

Color Graphics Adapter (CGA)

This is an older, virtually obsolete, computer video standard. CGA resolution is 640 x 200 pixels with a maximum of 16 colors.

Color Mapping

A method of converting high color computer images for use on lower color display units or projectors.

Color Palette

The total number of colors possible. Sometimes referred to in bits. (8-bit, 16-bit, 24 bit, etc.)

Color Temperature

A method of measuring the "whiteness" of a light source. Metal halide lamps have very high color temperatures compared to halogen or incandescent lights.

Composite Video

A type of video signal in which all information, the red, blue, and green signals (and sometimes audio signals as well), are mixed together. This is the type of signal used by televisions in the U.S. In contrast, most computers use RGB video, which consists of three separate signals for red, green and blue. In general, RGB video produces sharper images than composite video.

Compressed Resolution

A process in which a projector accepts a higher resolution signal and compresses the data down to fit its true resolution. Quality of compressed images varies tremendously. Many projectors offer compressed resolution for handling higher resolution than their true resolution. Some use a simple "line dropping" methods while others achieve varying degrees of higher quality with different "intelligent" algorithms.

Compressed SVGA

Unlike CRT based monitors, LCD and DLP projectors only have one "true" resolution. Many projectors in the market are VGA (640x480) resolution. To project an SVGA (800x600) image with a VGA projector, the original SVGA signal must be compressed down to VGA. This is done by interpolating the data, and trying to best display all the information with only two thirds of the pixels (307,000 vs. 480,000). The resulting image gives you the SVGA page size, but some sacrifice of image quality. The vast majority of people with SVGA computers find they will have more satisfying results by switching the output of their computer to VGA for use with a VGA projector.

Compressed SXGA

Found on XGA projectors, compressed SXGA handling allows these projectors to handle up to 1280x1024 SXGA resolution. As with compressed VGA and XGA image quality is reduced with compression. Mostly SXGA is used by Workstations (SUN, SGI, IBM, HP.), typically used in applications such as medical, life sciences and engineering.

Compressed XGA

Found on SVGA projectors, compressed XGA handling allows these projectors to handle 1024x768 XGA resolution. As with compressed SVGA, the quality of the compressed image is reduced. The quality of the compressed XGA image from a given projector is a key factor in the decision process for most people choosing an SVGA projector. This is true as the market shifts from SVGA computers to those with XGA screens.

Compression Mode

A method of displaying images in a reduced size format. See also Compressed SVGA, VGA and SXGA. A compressed image often has light and dark lines and text characters with thick and thin line widths.

Computer In(put)

Typical labeling of connector on a projector or panel where the cable from your computer plugs in.

Computer Out(put)

Typical labeling of connector on a projector or panel where the cable to your computer monitor is connected. This is not available on all projectors and is not usually needed when using a laptop.

Contrast

The difference between the brightest part of a projected image and the darkest.

Contrast Ratio

A method of measuring the dynamic range. A contrast ratio of 15:1 (passive matrix LCDs), offers washed out colors, little detail, and images that can barely survive with significant ambient light. Projectors with Active matrix TFTs have ratios to 100:1, DLPs from 125:1 and Poly-Si LCDs 200:1. By comparison transparency film (i.e. 35mm slides) have contrast ratios over 500:1.

Control Panel

A touch screen panel that is used in correlation with a videoconferencing room system that allows the presenter to toggle between various video, computer, and audio devices. It also can be used to control an electronic screen and room lighting.

Convergence

The alignment of the component red, green, and blue video images on a projected display system. If the convergence is incorrect, color fringes or "ghosts" appear on the projected image.

Data Rate

The rate or speed at which data is transmitted, usually stated in bits per second or Baud.

Depth of Focus

The ability of an imaging system to keep an image in focus when the object plane is NOT thin.

Device Driver

Software that allows a computer to communicate with an internal or external peripheral device, such as a printer, scanner or CD-ROM player.

Diagonal Screen

The method of measuring the size of a computer or television image. Measured from one corner to the diagonally opposite corner, a 9 FT high by 12 FT wide projected image has a diagonal of 15FT. Typically, in computer and video we assume that the diagonal dimensions are for the traditional 4:3 aspect ratio as in the previous example. Remember, the 4:3 aspect ratio is standard for Video and computer images, but some screens are square, others particularly wide.

Digital Camera

A camera that takes pictures and saves them in digital form. Can be reproduced on a computer or developed as hard copy pictures.

Digital Compression

Encoding data or digital information to use less storage space or to require less bandwidth for efficient transmission.

Digital Light Processing (DLP)

The name for a new technology from Texas Instruments: The technology inside is sometimes referred to as either "micro-mirrors", or DMD: It works in the same way ancient people used to signal each other by flashing sunlight off mirrors. However the modern version replaces the sun with a powerful lamp and uses hundreds of thousands of rotating mirrors, lined up in 800 rows of 600 mirrors each. Attach each of those 480,000 hinges to its own motor. The motors tilt their mirrors up to 20 degrees at incredible speeds. allowing the mirrors to modulate light from the lamp, and send the "modulated signal" out through a lens, on to a screen. Now comes the hard part - The 480,000 mirrors (actually 580,000 are used), hinges and motors are packed onto a "wafer" a bit larger than your thumbnail.

Digital Signal Processors (DSP's)

A specialized digital microprocessor that performs calculations on digitized signals that were originally analog and then sends the results.

Digital Video

Video where all the instructions for the images are in computer data form, i.e. bits.

Digitize

Process of converting analog information into digital information.

Direct Drive Image Light Amplifier (D-ILA)

A higher quality of LCD image projection.

Disk Pad

A device used to control movement of an icon (such as a cursor) across an image. A disk pad controls movement of the cursor by making it move in the direction corresponding to the part of the disk you press down on (relative to the center.) To clarify, press down on the disk at 2 o'clock, and the cursor will move on in that direction (toward the upper right) from wherever it had been.

Display

A screen that electronically presents numbers, characters, graphics, etc. transmitted from a personal computer.

Display Size

Display size is the diagonal size of an image display device. Typical laptop LCD sizes are 8.4" to 12.1" measured diagonally.

Distortion

An undesired modification of the original signal appearing in the output. Distortion can be caused by improper setup or poor quality equipment. Distortion appears as ghosting or off color images, or is heard as muffled or crackling sound.

Distribution Amplifier

An amplifier used to maintain a clean noise free signal to the projector over significant distances. Even with good heavily shielded cables, the range of video and computer signals is limited to a few dozen feet before noticeable degradation. Often projection using ceiling mounted equipment, a distribution amp may be needed even with shorter distances to eliminate the interference caused by electric conduits and equipment in the ceiling near the signal cable. Many distribution amps can also split the signal into 2 or more amplified signals for driving multiple projectors, projectors and monitors.

Dithering

The method of mixing up neighboring pixels or consecutive frames of pixel information in a random fashion to create the effect of many intermediate levels of color.

DMD Technology (DLP)

see Digital Light Processing

Document Camera

A visual tool that allows the user to project an actual 3-D object to an external projection device.

Dots Per Inch (DPI)

The higher the DPI, which delivers more information, the better the resolution. DPI is typically used to determine the resolution on a printer.

Double Super Twist Nematic (DSTN)

A process where two separate LCD plates are combined to form a single panel.

Dual Scan Passive Matrix

Newer version of the original passive matrix technology, where the screen is controlled by two processing systems. A faster than "single scan", response is still not as fast as active matrix. Not recommended for multimedia or video applications. Dual scan is used in the least expensive LCD panels.

Dynamic Range

The ability to "reproduce" the full range of an inputted signal. If that range is limited, it will be difficult to distinguish between pure white and the lightest grays. Subtle details disappear without adequate dynamic range. See also "color dynamics"

Electronic Whiteboard

A whiteboard that has the ability to electronically scan itself and the images can then be transferred to computer, edited, printed, emailed or faxed. Many electronic whiteboards will interface with projectors, allowing annotating of presentations and some control of the computer.

Enhanced Graphics Array (EGA)

This is the second generation of the CGA standard that it gave PCs, XTs and ATs greater resolution (640 x 350 in all models). Like CGA, it is virtually obsolete.

Extended Digital Subscriber Line (EDSL)

In an ISDN application, the digital channel that delivers Primary Rate Access or 23B+D service to an individual subscriber.

Focal Length

A fundamental measure of lens performance, usually expressed in millimeters.

Frame

A single complete picture in a film recording or video.

Frame Grab

Electronically capturing and storing one screen of information.

Frequency

The number of cycles per unit of time.

Front Projection

Projecting onto a reflective surface of an opaque screen material for viewing from the same side, as opposed to rear projection.

Full frame

Generally refers to as filling a computer monitor with a video clip. Using the entire screen.

Full frame, 30 frames per second (fps)

Running full video frames on a computer at 30 frames per second, providing the same seamless video as movies, video tape and TV.

Gradation

The slow change of a colors density; a change in tone or texture, etc., between adjacent areas of an abject or the corresponding image.

Hard wired remote

A remote control that has a connecting cable to the device it controls. Often used at a podium or lectern.

HDTV

High Definition Television, a term used to describe advanced production and delivery systems.

High Gain Screen

A screen that uses one of many methods to collect light and reflect it back to the audience. This results in an image which is considerably brighter than the image on a white wall or matte screen. The disadvantage of a high gain screen is often a narrower viewing angle. High Gain screens are more expensive than Matte screens, but attention to the screen can make a big difference, particularly in "tough" environments such as trade shows.

Hz, (KHz, MHz)

Hertz or (Kilohertz or Megahertz). Cycles per second. (Kilo = 1,000, Mega = 1 million). These terms are used to express the frequency of an electrical signal.

Hard Shell Carry Case

Typically used for shipping (ATA approved).

Image Compression (Compressed)

Compresses higher resolution images into lower, for example compressing a SVGA (800 x 600) down to VGA (640 x 480).

Infra-red remote

The traditional remote control, it transmits infrared light, like a television remote. Typical range is limited to 30 or 35 feet. Infrared requires line of site or a bounce off of a hard surface. These signals from this type of remote control cannot pass through walls.

Integrated Services Digital Network (ISDN)

Standard digital service capability that includes one or more circuit-switched communication channels capable of carrying digital voice, data, or image signals, a packet-switched channel for out-of-band signaling and control, plus a collection of standard and optional features that support information productivity for the user providing higher-speed Internet access than analog systems.

Interactive

Employing the active participation of the user in determining the flow of the multimedia program.

Interface

To connect normally incompatible components so that the signal from one is readable by the second.

Interlacing

A technique used for the display of live video and some computer graphics whereby the image is displayed in horizontally stacked lines known as fields.

International Power Supply

A device that can operate under a variety of power requirements. Some units are "self-switching", they will automatically switch to whatever power source you plug it into. Others will have to be switched (internally or externally) to accommodate a different voltage or cycle range.

Invert Image

Electronically flips the image from top to bottom, to compensate for ceiling mounting a projector upside down, as most projectors have "keystone" correction built in to compensate for the distortion created by "pointing up" from the table to the screen. The image must be inverted when the projector is hung upside down from the ceiling. Most projectors are operated with the lens about even with the bottom of the screen in a "table top position", or even with the top of the screen when ceiling mounted.

IR (Infra-Red)

A type of wireless transmission using infrared light waves.

IR communication standard

A standard for wireless communicating with peripherals (printers wireless keyboards, pointing devices) and a computer. This feature is becoming common on laptop computers.

Joint Photographic Experts Group (JPEG)

Standard for maximum efficiency of coding of most still images.

Joystick

A device used to control movement of an pointer icon (cursor) across an image. Each physical location of the "stick" corresponds to a location on the screen.

Keystone

The "wedge" shape picture caused when the projector is not even with the horizontal or vertical center of the middle of the screen. Most data and video projectors use optical and electronic methods to eliminate this problem.

Laptop

A small portable computer with a self contained LCD display.

Laser Pointer

A small pen or cigar sized device that contains a small battery powered laser, which can project a small, red, high intensity spot of light that is immediately very visible on the screen.

Lavalier Microphone

Microphone attached to the presenter's jacket or shirt. Very small an inconspicuous. Many times they are wireless to allow the presenter to move around the room.

LCD

Liquid Crystal Display - a glass panel display that works by controlling the opacity of segments of itself by varying the electrical signal. Each individual segment called a pixel, acts as a shutter, to control the amount of light being passed through.

LCD Projector

A projector using an LCD to modulate the light.

LCD Projection Panel

The predecessor to today's self contained projectors. They lack their own light source, and instead, sit on top of a overhead projector. Although panels are light (5-8LB.), even on specially designed, extremely bright, overhead projectors, their image is not as bright as today's self-contained projectors. Therefore use is limited to darkened rooms on small screens.

Light Valve

Another projection technology, found in the "big" systems, these units are extremely bright and capable of producing "stadium size" images.

Long Throw Lens

A lens designed for projection from a very long distance. Long throw lenses would be used in a projection booth in the back of a theater, etc. A typical long throw lens might have to be 50 to 100 ft. back to project a 10 ft. diagonal image.

Luminance

The relative brightness values of a particular object in a scene.

Lux

A unit for measuring light, as methods of measurement are not standardized, numbers provided by manufacturers usually do not provide all necessary information to compare one product to another. A preferred unit of measuring light output is the ANSI Lumen.

Maximum Distance

The longest distance from the screen that a projector can properly focus the image.

Maximum Image Size

The largest image a projector can throw in a darkened room.

Megabyte

1 million, or 1,048,576, bytes or characters. It is abbreviated as MB or Meg.

Memory

The device in the computers main unit that stores information, both permanently (hard-disk) or temporarily in microchips (RAM or random-access memory).

Menu Driven

Refers to the type of controls on a projector. The user will be offered an on screen menu display of major categories such as Computer, Video, Audio, Display, Options. After selecting one, you will get another menu of choices with items like brightness, contrast, etc. after select one of these and you can then adjust it. Most projectors are menu driven but also offer the most widely used functions in a non-menu fashion, such as separate control buttons for volume, brightness, and contrast, as well as switching between sources.

Metal Halide Lamp

The type of lamp used in many medium and all high-end portable projectors. These lamps emit a very high amount of light for the amount of power they consume. Unlike many other types of lamp, they slowly lose intensity (brightness) as they are used. As they get older the corners of the projected image becomes noticeably darker. Metal halide lamps usually last between 400 and 600 hundred hours. They usually cost from $300 to $600 retail, but most are around $500. These lamps output a very "hot" temperature light, Their whites are "extremely" white and make Halogen lamps whites look yellowish in comparison.

Microprocessor

An electronic circuit, usually on a single microchip, that performs arithmetic, logic, and control operations, customarily with the help of internal memory, also on the chip.

Minimum Distance

The closest position that a projector can focus an image onto a screen.

Minimum Image Size

The smallest image a projector can create.

Motion Picture Experts Group (MPEG)

A standard form of coding used for stored video and television. It is designed for maximum efficiency on sequences of continuous-tone images where there are known redundancies from one image to the next, such as movies.

Multimedia

A vague expression that indicates the ability to integrate several different types of media. Media types include, video, photos, sound, clip art, graphic design, text and more.

Multimedia Computer

Generally refers to a computer that has a minimum set of features including, active matrix display, a sound card and speakers, fast video, and usually a CD-ROM or DVD player built in.

National Television Standards Committee NTSC)

Usually refers to the standard for video and broadcasting used in the United States, Canada and several other countries. The NTSC standard is older and produces lower resolution than other television systems used in the world. It is incompatible with other television standards.

Noise

An unplanned, unwanted energy into a communication path, which can change the informational signal.

Non-Interlaced

Each line of an imaged is scanned during each total vertical (full) screen refresh, this process greatly reduces image flicker, resulting in reduced eyestrain.

Overhead Projector (OHP)

A device consisting of light source, a glass platform and a focusable lens assembly, designed to project to a screen, images from transparencies. Overhead projectors for LCD panels are particularly bright, and start at about 3000 lumens, or about 2 to 4 times as bright as most older overheads.

Overlay

The ability to superimpose computer generated graphics and/or text on motion or still video.

PAL

Phase Alternate Line. The PAL television system used extensively in Great Britain and western Europe. It is incompatible with other television standards.

Palette

The number of colors available for use in creating an image.

Parallel

A method of transmitting several bits of data simultaneously through a communications channel.

Passive Matrix LCD

The original LCDs, these are controlled by a single processing system, for the whole screen, unlike active and poly-silicate panels, which have discrete circuits for each "pixel". This results in a panel with less color dynamics and lower contrast ratio. A major drawback of passive matrix LCD is they are very slow. With a passive LCD laptop computer, any moving screen object, such as the cursor, may disappear until you stop moving it. Very few projectors still use a passive matrix display.

Peripheral

External devices controlled by the computer, e.g. printer, keyboard, mouse.

Pixel

Short for picture element. The smallest element of a raster display represented as a point with specified color and intensity.

Plasma Monitor

New video technology that produces a crisp, clear picture with plasma gas pixels allowing for a thin projection panel.

Polysilicon LCD

The latest LCD technology for LCD projectors. Polysilicon is usually 3 separate layers of LCDs, for red, green and blue light. This results in increased color dynamics, with high contrast ratios around 200:1. Poly silicon is ideal for multimedia applications.

Power Lens

Typically a motorized lens that allows adjustment of focus and zoom from a remote control.

Rear Screen Projection

The projector is placed behind a translucent glass or plastic screen, out of sight of the audience. It projects onto the back screen and the audience sees on the front. Some large screen projection monitors use rear screen projection.

Refresh Rate

The number of times the screen image is "painted" or refreshed per second, expressed in Hz.

Resolution

Number of dots or pixels per unit of area. The greater the pixels per unit area the higher the resolution, giving more detail.

Response Time

The reaction time for a pixel to turn on and off. An active-matrix LCD projection panel's response time is fast enough to display full-motion video and rapid mouse cursor movements.

Reverse Image

Reverse image is a feature found on many projectors which flips the image horizontally. Reverse image is needed for rear projection.

RGB

Red, Green, Blue, A video or data signal in which the component color information of a video signal is carried as separate signals. Also used to describe the type of monitor.

Scan Converter

A device used to convert the computer video output to a television representation, or vice versa.

Scan Rate

Referring to the horizontal or vertical rates, expressed in Kilo Hertz(kHz).

SCSI

Small Computer Systems Interface, pronounced "scussy". A device independent interface used for a wide range of peripherals.

SECAM

A television standard for video and broadcasting. Used mainly in France and the former East Bloc countries. Higher resolution than NTSC. It is incompatible with other television standards.

Serial

A method of transmitting data bit-by-bit through a single communications channel.

Short Throw Lens

A lens designed to project the largest possible image a short distance. They are often required for rear projection, where the depth behind the screen is limited.

Soft Carry Case

A type of case used for casual transport of a projection unit.

Source

An input feeding a signal to a projector.

Sun Workstation Resolution

Most Sun workstations use 1152 x 900 as their default resolution.

STN

Super Twist Nematic.

SVGA (Super VGA) Resolution

SVGA refers to a 800 x 600 pixel display, regardless of the number of colors available.

S-VHS Input

S-VHS is a standard for transmitting video information. It provides significantly better image quality than composite video.

S-Video

A form of electrical signal used to transfer video between components. S-video keeps the luminance and chrominance component signals separate on different signal wires, using multi-pin connectors. S-video leads to higher image quality, compared to composite video, because it avoids the degradation that results from combining and separating the components.

Switcher

Allows multiple signals to be sent to one projection display used in system installations.

SXGA Resolution

SXGA refers to a monitor resolution of 1280 x 1024 pixel display, regardless of the number of colors available.

Sync

he way the projector reads the video signal.

TFT

Thin Film Transistor. This is a developing technology that attempts to place the controller an LCD panel directly on the surface of the glass.

Touchscreen

A display device that acts as an input device by responding to the touch of the user.

Track Ball

A device used to control movement of an icon (such as a cursor) across an image. Rotating the ball in a direction corresponds directly to the mouse's movements.

Transmitivity

The percent of the light that is transmitted off the stage of the overhead projector that reaches the screen at a given distance. Typically, LCD projection panels are able to use less than 10% of the total light available.

True Color

A term for 24 bit color (16.7 million colors - any combination of 256 shades each of Red, Green, and Blue).

TSTN

Triple Super Twist Nematic. Where three separate LCD plates are combined to form a single panel.

Videoconferencing

A technology that allows you to have a multi-site meeting or conversation through the use of a camera, monitor, and phone line.

VESA Standard

A set of display specifications agreed upon by the Video Electronics Standards Association. A non-profit group organized to define and improve computer graphics standards.

Video

The capability to project images from a VCR, laser disc, or PC with CD-ROM drive.

Video Standards

A variety of broadcast and video standards, including NTSC, PAL, SECAM. Multiple Video Standards is an important feature if you plan to use your projector in other countries.

Viewing Angle

Maximum angle at which a viewer can clearly see an image projected on a screen.

VGA

Video Graphics Array. 640 x 480 resolution.

VGA cable

The cable used to connect your computer to a projector.

VGA Resolution

VGA resolution normally refers to a 640 x 480 pixel display, regardless of the number of colors available.

Window

A portion of the computer screen in which a video image or other information is presented.

Workstation

A desktop computer typically dedicated to a single engineer. Usually a high-end machine.

Workstation Resolutions

Generally a number of different resolutions, higher than 1024 x 768. Most widely used: 1280 x 1024, 1152 x 900 and 1600 x 1200. Some workstations can be set to the lower resolution of 1024 x 768, but are not normally operated there.

WYSIWYG

What You See Is What You Get. This refers to a graphical display mode in which the page on the display screen represents exactly what will appear on the printed page.

XGA Resolution

One of several terms used to describe 1024 x 768 resolution.

Y-Cable

Most computers have only one monitor output. Subsequently, a special cable is necessary to split the monitor signal so it will work simultaneously with both a monitor and a projector.

Zoom

An adjustment to the area of the projected image (screen size).

Zoom Lens

A lens with a variable focal length. This translates to being able to adjust the size of the image on a screen by adjusting the zoom lens, instead of having to move the projector closer or further.

Zoom Lens Ratio

The ratio between the smallest and largest image a lens can projector from a fixed distance.