Tech Info1080p
1080p is ATSC high definition 1920 x 1080 progressive scan video format where a complete frame of video is delivered at either 60 or 24 frames per second.
16:9
Aspect ratio of an HDTV signal which is 16 units by 9 units, whatever size those units may be. In the film trade aspect ratios are described in relation to one, which means this aspect ratio is described as 16:9 or 1.78:1.
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 educational software suites. These projectors are not compatible with the HDMI 1.4 3D specification used on 3D Blu-ray players and set-top boxes.
Ambient Light
Light within the room or space coming from non-projector related sources (windows, overhead lights…etc.). The higher the Ambient Light present, the higher ANSI Lumen rated projector needed
ANSI
American National Standards Institute. A private organisation that coordinates and administers various voluntary consensus standards such as ANSI lumens. The first ANSI standard was for pipe threading in 1919 when it was called the American Engineering Standards Committee
ANSI Lumens
ANSI lumens is a measurement of the overall brightness of a projector. Because the centre of a projected image is brighter than the corners, ANSI lumens is the most accurate representation of the image brightness. ANSI lumens are calculated by dividing a square meter image into 9 equal rectangles, measuring the lux (or brightness) reading at the centre of each rectangle, and averaging these nine points
Aspect Ratio
The ratio of image width to image height. Analogue television is 4:3 or 1.33:1. Panavision or Cinemascope is 2.35:1 with 1.85:1 being quite common as well. Widescreen displays are 1.78:1 or 16:9 times the height. For example, if you want an image 40 inches high then you need a screen that is at least 40 * 1.78 inches wide or 71 inches. 16:10 is fast becoming the new standard native format for most monitors and video display devices.
AVI
Audio/Video Interleave. The file format for Video for Windows (VfW). Used in conjunction with a codec to play back video. Format dictates how video and audio are stored in relation to each other but not the particular compression scheme used, which is handled by the codec.
Brightness
Overall light output from an image. While a brightness control can make an image brighter, it is best used to better define the black level of the image.
Calibrate
To adjust with reference to a standard.
Contrast
Contrast increases as the white point increases. Increasing the white point creates a greater difference between white and black.
Contrast Ratio
The ratio between white and black. The larger the contrast ratio the greater the ability of a video device to show subtle colour details and tolerate ambient room light. There are two industry methods used: 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 video devices make sure you are comparing the same type of contrast. Full On/Off contrast will always be a larger number than ANSIcontrast for the same video device.
DisplayPort
DisplayPort is a digital display interface developed by the VESA. The interface is primarily used to connect a video source to a display device such as a computer monitor, though it can also be used to transmit audio, USB, and other forms of data. Displayport can be used to transmit audio and video simultaneously. The DisplayPort signal is not directly compatible with DVI or HDMI but passive adapters can be used to adjust the signal levels and convert the connector style
DLP
DLP (Digital Light Processing) is a commercial name for a display technology from Texas Instruments (TI). The technology inside is often referred to as DMD (Digital Micro-Mirrors). It consists of an array of mirrors where each mirror represents a pixel element. For example, a high-definition DLP projector or rear projector with 1920 x 1080 pixel resolution would have over 2 million tiny mirrors. Each mirror is attached to an electronically driven hinge that controls the amount of coloured light that is reflected from the mirror into the projection lens and onto a screen. Projection systems using DLP technology use 1 to 3 DMD devices.
Dynamic Range
The ratio between the highest and lowest levels a device can perform. For a video device it is a measure of contrast ratio. For an audio device it is usually stated in dB.
F-number
Refers to the amount of brightness that a lens allows through the screen. Ideally, the f-number should not deviate much from different zoom angles.
Focal Length
The distance from the surface of a lens to its focal point. A smaller focal length indicates a wider-angle lens.
Focus
A point at which rays of light converge. It is adjusted to clarify a blurry image.
HDMI
HDMI (High Definition Multimedia Interface) is an uncompressed, all-digital audio/video interface that supports audio/video sources such as a set-top box, DVD player, A/V receiver, and video monitors such as a digital projector or digital television (DTV). HDMI is backward compatible with DVI 1.0 specification and supports HDCP.
HDMI supports standard, enhanced, or high-definition video, plus multi-channel digital audio, and interactive controls on a single cable. It transmits all ATSC (Advanced Television Systems Committee) HDTV standards and supports 8-channel digital audio.
JPEG
Joint Photographic Experts Group. Name of association that created the image file standard of the same name. A compression scheme for storing high quality, full-colour images. Also used as a video format under the guise M-JPEG of which a variant is used for DV video.
LED
Light Emitting Diode. A light generating technology that uses a semiconductor diode that emits monochromatic (single colour) light when charged. LEDs are used in remote controls that are used to control electronic devices such as large displays. They are also used in pocket projectors as a light source, large outdoor electronic displays, and as indicators on electronic devices such as power supplies and cameras.
LED Lamp
A type of projector lamp that uses one or more LEDs as its light source. The benefit of LED lamps is their long life.
Lens Shift
The purpose of "lens shift" is to eliminate keystone correction and provide greater flexibility in the placement of the projector relative to the screen or the alignment of stacked projectors. This is accomplished by allowing the optical lens to be physically shifted vertically and/or horizontally. These adjustments may be manual or motorized depending on the projector.
Lumen
A measurement unit of total illumination. Typically a 100-watt light bulb has a 1700 lumens output over a wide area. Projector light output is measured in ANSI lumens. A projector with a higher lumen number will produce a brighter image for a given image size.
Long Throw Lens
A long throw lens allows greater distance between the projector and the screen while being able to maintain the image size and brightness of a shorter throw lens for any given projector. Depending on the room, a long throw lens may be required due to mounting constraints nearer the projected image.
Maximum Resolution
Maximum Resolution refers to the highest resolution that a given display device can support. If the Maximum Resolution exceeds the Native Resolution, the image is usually scaled to match or approximate the Native Resolution of the projector. Some display devices allow pan and scan where rather than scaling the image, the display devices allows you to use the native resolution of the display to view portions of the higher resolution image. Scaling reduces the image resolution and produces some artefacts in the image that are more apparent when viewing text than graphics or video
Memory Card
A feature on some projectors that allows photos, documents and/or presentation material to be projected using a memory card and thereby eliminating the need of a computer.
Native Aspect Ratio
Nearly every projector or display today will support multiple aspect ratios. This means each device has a native aspect ratio that is optimized for specific viewing material. Images shown in native aspect ratio will utilise the entire resolution of the display and achieve maximum brightness. Images shown in other than native aspect ratio will always have less resolution and less brightness than images shown in native aspect ratio.
Native Resolution
Native Resolution is the number of physical pixels in a display device. For example, an XGA display has a native resolution of 1024 physical pixels of resolution horizontally and 768 pixels vertically or 786,432 total pixels
Pico Projector
A marketing term to describe a small hand held projector that can fit in your pocket. A Pico Projector can be a stand-alone device that connects to a computer or other video device or a projection module that is integrated with a phone, portable computer, MP3 player or other small device.
Power Output
The amount of power sent to drive the device. Peak output is quite often specified, which is somewhat misleading compared to the average amount of power a device can continuously produce (RMS rating).
Projector
A projector is a device that integrates a light source, an optics system, electronics and display(s) for the purpose of projecting an image from a computer or video device onto a wall or screen for large image viewing. These devices attach to a computer or video device as you would connect a monitor or television
Resolution
A measure of the ability of a display or sound system to render detail.
Short Throw Lens
A lens designed to project a large image from a short distance
Throw Distance
Throw distance is the measurement from the projector's lens to the screen. A projector with a zoom lens will have a range of throw distances for any given image size, while a projector without a zoom lens will only be able to project one image size at a given distance from the screen.
Throw Ratio
For any given projector, the width of the image (W) relative to the throw distance (D) is known as the throw ratio D/W. So for example, one of the most common projector throw ratio is 2.0. This means that for each foot of image width, the projector needs to be 2 feet away or D/W = 2/1 = 2.0.
USB
Acronym for Universal Serial Bus, a peripheral connection interface for low-speed devices. Notable for its easy swapability.
UXGA
Resolution of a computer generated image. A UXGA projector will be able to display a 1600x1200 image from a computer running in a UXGA video mode. If the computer is not running in a UXGA video mode, typically the projector will resize the image to 1600 x 1200.
Video Compatibility
Ability of computers and projection units to transmit and receive data to read and/or project various video tape standards, such as NTSC, PAL, SECAM and S-VHS
VGA
VGA (Video Graphics Array) is 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.
Watt
A unit of power. Volts multiplied by amperage equals watts.
WiFi
Wi-Fi is 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 specifications currently in the family: 802.11, 802.11a, 802.11b, and 802.11g
WMA
Windows Media Audio. Similar to MP3 but considered a more efficient compressor allowing for smaller file sizes for a given quality.
WXGA
WXGA defines a class of XGA displays with a width resolution sufficient to create an aspect ratio of 16:9. A WXGA display has 1366 to 1280 pixels horizontally and 768 to 720 pixels vertically.
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 placements that can produce the same size image.
Zoom Ratio
Zoom 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. 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 fixed lens, and the higher the ratio, the less light output.
