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Glossary

Find out what the technical jargon means.

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A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A
  • Aliasing In digital video, insufficient sampling or poor filtering of the signal causes aliasing. Defects typically appear as jagged edges on diagonal lines and twinkling or brightening in picture detail.
  • 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.
  • Auto Source The ability of the projector to automatically recognize and synchronize to the horizontal and vertical scan frequencies of an input signal for proper display.
B
  • Black level More commonly referred to as "brightness", the black level is the level of light produced on a video screen. The level of a picture signal corresponding to the maximum limit of black peaks. The bottom portion of the video wave form, which contains the sync, blanking and control signals. The black level is set by the "brightness" control.
C
  • Carl Zeiss Famed and renowned manufacturer of high quality lenses for cameras and projectors
  • Colour wheel Colour wheels are used in DLP technology. A wheel through which light passes, turning the light to different colours alternately. The speed at which the alternate colours are displayed results in a full colour image being perceived by the brain.
  • Component Video - Component Video is a type of analog video information that is transmitted or stored as two or more separate signals (red, green, blue). Component Video can be contrasted with Composite video in which all the video information is combined into a single signal such as a TV broadcast. Currently, Component Video connections are gradually being superseded by the higher quality digital DVI and HDMI interface.
  • Composite video - An all-in-one video signal - lowest video quality
  • Connectivity - Refers to the input and output ports and wireless ability of the product
  • Contrast Ratio - The measurement of the difference in light intensity between the brightest white and the darkest black. Higher Contrast Ratios generally result in richer images, and are particularly preferable for home cinema use.
D
  • Decoder A device used to separate the RGBS (red, green, blue and sync) signals from a Composite video signal.
  • DVD Digital Versatile Disc. Same physical size as a compact disc but has a capacity to hold a minimum of 4.7GB of data, 9.4GB if dual layer and/or dual sided. DVD-Video discs can hold about 4 hours of video on a dual layer disc depending upon the amount of compression applied. It uses MPEG-2 compression at a maximum rate of 9.2 Mbps with most video compressed at about 4Mbps at 720x480 pixels. All players support AC-3 (Dolby Digital), PCM, and MPEG-2 audio with up to 8 separate tracks. DTS is usually supported but isn't mandatory to the format. DVD-Audio supports up to 6 channels of 24 bit, 192KHz sampled PCM audio.
  • DVI-D - A variant of the DVI (Digital Video Interface) connnection standard. DVI is a very high quality, digital connection which is typically found in higher-end PCs designed for high quality graphics, and Apple Macs. It can be found in some home cinema projectors but HDMI is now becoming a more common standard for this market as it also carries audio.
E
  • Eco-mode A menu function to extend Lamp life and reduce energy consumption by slightly reducing brightness. Typically a 20% reduction in brightness can increase Lamp life by up to 50 per cent
H
  • HDMI High-Definition Multimedia Interface. A modern, digital connection that carries both video and audio signals. Effectively replaces the old SCART connection in a more compact, higher definition format.
  • High Gain Projection Screen Material that reflects more light than matte material. Increases a projector's light output at the expense of uniformity.
I
  • I/O Input / Output
  • Infra Red Remote An infra-red (IR) remote control transmits in the spectrum of infra-red light, such as a television remote. Unlike RF remotes, IR remotes must point at the receiver (line of sight). Typical range is limited to 30 feet including the distance to and from reflected surfaces. For example, if you are controlling a projector and you point the remote at the screen which is 12 feet from you and the projector is 10 feet, the total distance is 22 feet. Most projectors have a IR sensor in both the front and rear of the projector, whereas, flatscreens generally have a single IR sensor in the front of the unit. When working at or near the maximum distance, pointing right at the receiver is necessary. IR remotes must have clear path or reflected path to the receiver to operate.
  • Inter-Connects - Any cable or wire running between two pieces of A/V equipment. For example, RCA terminated cables connecting pre/pros and amps.
  • Interlaced - Process of alternating scan lines to create a complete image. In CRT displays, every second field/frame is scanned between the first field/frame. The first field represents the odd lines; the second field represents the even lines. The fields are aligned and timed so that, with a still image, the human eye blurs the two fields together and sees them as one. Interlace scanning allows only half the lines to be transmitted and presented at any given moment. A 1080i HD signal transmits and displays only 540 lines per 60th of a second. 480i NTSC transmits and displays only 240 lines per 60th of a second. Motion in the image can make the fields noticeable. Interlaced images have motion artefacts when two fields don't match to create the complete frame, often most noticeable in film-based material.
  • Interlacing - A video frame is made up of two fields. Interlacing is the process of scanning the picture onto a video screen whereby the lines of one scanned field fall evenly between the lines of the preceding field
L
  • Lamp life - Lamp life is usually measured in hours and determines the amount of hours left until you need to replace the lamp.
  • LCD - Liquid Crystal Display. A display that consists of two polarising transparent panels and a liquid crystal surface sandwiched in between. Voltage is applied to certain areas, causing the crystal to turn dark. A light source behind the panel transmits through transparent crystals and is mostly blocked by dark crystals.
  • Lens Shift - Displacement of the lens with the prism (horizontal or vertical) or vice versa, resulting in the centre of the image being offset from the centre of the lens. Lens Shift is used to help eliminate key-stoned images and geometrically align images when multiple projectors are used simultaneously.
S
  • SCART - Analogue AV connection used commonly across Europe, especially with televisions and DVD players but less commonly with projectors. An advantage of SCART is that it carries both video and audio in one cable. SCART will be overtaken in popularity by its digital equivalent, HDMI.
  • SVGA - The projected image is made up of 800 x 600 pixels.
  • SXGA - The projected image is made up of 1280 x 1024 pixels
  • SXRD - Silicon X-tal Reflective Display : panels with rapid 5msec response time and over 6 Million pixels with narrow spacing and high density - no screen door effect
U
  • UXGA - The projected image is made up of 1600 x 1200 pixels
W
  • WUXGA - The projected image is made up of 1920 x 1200 pixels
X
  • XGA - The projected image is made up of 1024 x 768 pixels