Red, green and blue light. When all three additive primaries are combined at 100 per cent intensity, white light is produced.
Any light in the viewing room created by a source other than the projector or screen.
The ratio of height to width of a frame or screen. In a 4:3 aspect ratio, the width of the image is 4/3 times the height. Most current TV and computer video formats are in a 4:3 aspect ratio. A 15 inch monitor is 12 inches wide by 9 inches high (9*4/3 = 12). A resolution of 640x480 is a 4:3 format (480*4/3 = 640). SXGA is a 5:4 aspect ratio is (1280x1024), HDTV is 16:9 for that movie theater feel, and 35mm slides are 3:2.
ANSI stands for American National Standards Institute. It is a standard used for measuring the light output from a light source.
Instrument for measuring colourimetric quantities, such as the tristimulus values of a colour stimulus.
Measurement of colour output from a projector. The higher the Colour Brightness the more vivid and realistic the colour. Also known as Colour Light Output.
The range of different colours that can be interpreted by a colour model or generated by a specific device.
Colour Light Output or CLO
IDMS 15.4 standard for the measurement of the colour light output from a projector. Also known as Colour Brightness. This indicates, in lumens, how bright the a digital projector’s colours (red, green and blue) are.
The total number of colors available, expressed in bits per pixel.
Part of the inside mechanism of a DLP projector used to create colour.
The level of variation between light and dark areas in an image.
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 industry: 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 projector.
Photoreceptor cells in the retina of the eye responsible for colour vision.
Subtractive colours of Cyan, Magenta and Yellow.
A colour model used in 4-colour offset printing, with the K standing for Black to avoid confusion with Blue.
Optical device used in a 3LCD projection system to divide light into multiple beams. Each dichroic mirror reflects specific wavelengths of light while allowing all other wavelengths to pass through. For example, a dichroic mirror may reflect red light but allow blue and green light to pass through.
A Digital Micromirror Device is an optical semiconductor used in DLP projection technology.
Abbreviation for the Digital Light Processing projector technology from Texas Instruments.
Abbreviation for International Display Measurements Standard. The IDMS is the document for standard measurement procedures to quantify electronic display characteristics and qualities from the Society for Information Display (SID), a body comprised of the top scientists, engineers, corporate researchers, and business people of the display industry. To download visit: http://icdm-sid.org/
The standard measurement test for Colour Light Output.
The basic colour of an object, such as "red", "green," etc.
International Colour Consortium, industry body responsible for the ICC profile specification and colour management architecture.
A test for colour blindness.
Unit of measurement for colour temperature.
A projector’s ability to correct a trapezoid image being shown, enabling the projector user’s audience to view a rectangular image rather than one with a wider top or bottom.
A means of moving a projector lens up, down and sometimes side to side without distorting the image. Useful for fine picture alignment and when stacking multiple projectors.
A measure of the total "amount" of visible light emitted by a source.
A photometer used for measuring low light levels.
One lumen per square meter.
Short for picture element. The smallest element in a displayed image. A color pixel is a combination of red, green and blue subpixels. Total pixels are usually expressed in horizontal x vertical dimensions (e.g. 640 x 480).
On 1-chip DLP projectors, the rainbow effect is created by the inability of the DLP colour wheels to refresh pixels fast enough, resulting in some colour separation on the edges of fast-moving objects. Only seen by some people.
Additive primaries of Red, Green and Blue.
Measurement of how finely an image is resolved by the number of pixels. Number of pixels (or dots) per unit of area, measured in number of pixels wide by the number of pixels high that can be displayed on the screen or monitor. More pixels per unit of area produce a higher resolution.
Colour space originally designed for the web.
Cyan, Magenta, and Yellow. When all three subtractive primaries are combined at 100% on white paper, black is produced. Used in printing and with ink technologies.
Saturation, Chroma, Colourfulness
Saturation Colourfulness and Chroma are related but distinct concepts referring to the perceived intensity of a specific colour. Colourfulness is the degree of difference between a colour and gray. Chroma is the colourfulness relative to the brightness of another colour that appears white under similar viewing conditions. Saturation is the colourfulness of a colour relative to its own brightness.
Instrument measuring the intensity or transmitted light as a function of wavelength or colour.
Super Video Graphics Array, the number of pixels a projector is capable of displaying in a standard 4:3 aspect ratio of 800 Horizontal, 600 Vertical totaling 480,000 pixels. AKA Super VGA. Refers to a computer signal that is higher than the standard VGA resolution of 640 pixels by 480 lines with 16 or 256 colors. SVGA graphics cards may output resolutions such as 1024 x 768, 1280 x 1024, 1600 x 1200 pixels or higher, with 16.7 million colors displayed.
SXGA & SXGA+
Super XGA, standard screen resolution of 1280x1024 pixels. SXGA was common on standard monitors, but provided a 1.25:1 aspect ratio, compared to the more common 1.33:1 (4:3) ratio. SXGA+ was a 1400x1050 resolution, which is an exact 1.33:1 ratio with total pixels of 1,470,000
AKA Thin Film Transistor. A technology used to make Active Matrix LCD panels wherein each pixel has its own transistor switch.
Throw Distance or Throw Ratio
Length of the projection beam required for a projector to produce and image of a desired size. The ratio of the screen width to the distance to the screen (throw).
Ultra Extended Graphics Array is 1600 pixels horizontally by 1200 pixels vertically (1600 x 1200). This amounts to a total of 1,920,000 pixels on the screen in a 4:3 aspect ratio.
VGA Resolution normally refers to a 640 x 480 pixel display, regardless of the number of colors available. Originally VGA was 640 x 480 and 16 colors.
Wide Ultra XGA, a wide screen resolution of 1920x1200 or 1920x1080 pixels in a 16:10 aspect ratio
Extended Graphics Resolution, the number of pixels a projector is capable of displaying in a standard 4:3 as aspect ratio of 1024 Horizontal, 768 Vertical totaling 786,000 pixels. Acronym for Extended Graphics Adapter. A standard introduced by IBM that includes VGA as well as resolutions up to 1024 pixels by 768 interlaced lines.
Measurement of White Light Output of a projector without regard to colour.
A 16:9 aspect ratio image of 1280 x 720 pixels in progressive non-interlace mode. Total pixels of 921,600.
A 16:9 aspect ratio image of 1920 x 1080 pixels in progressive non-interlace mode. Total pixels of 2,073,000. This resolution is commonly referred to as 1080p or Full HD.
Abbreviation for 3-chip Liquid Crystal Display.