| Active 3D |
Active 3D involves a single projector rapidly alternating between displaying the left eye image and the right eye image. The frequency is coordinated with a pair of shuttered glasses which block the light to the opposite eye at the same rate. With active 3D it isn’t necessary to use a projection surface with polarisation retention. |
| Ambient Light |
Ambient light is the amount of unwanted light in a room that can affect the projection in a negative way. Ambient light can come from windows or from room lighting. |
| ANSI-Lumen |
Lumen is the unit of luminous flux, a measure of the power of light perceived by the human eye and the light output of projectors. The unit of measure is Lumens. The standardization for this measurement has been established by the American National Standards Institute (ANSI). |
| Aspect Ratio |
An aspect ratio is the relationship between the width and height of an image. Common aspect ratios are Video (4:3), HDTV (16:9), Wide (16:10), Cinemascope (2.35:1) and Square (1:1). |
| Barrel Distortion |
Image magnification decreases with distance from the optical axis. This creates an image which has been mapped around a sphere (or barrel) where lines do not go through the centre of an image but are bowed outwards. |
| Black Drop |
Black Drop is the extended black border above the viewing area used to position the viewing area at a the appropriate height. |
| Brightness |
Brightness is an attribute of visual perception in which the projection screen reflects light. |
| Cancellation / Extinction |
Cancellation and Extinction refer to differentiating between one image and the other. It describes the lack of noise in a signal, or the lack of the left eye image being seen by the right eye. |
| Contrast |
Contrast is the difference between the brightest white and the darkest black. |
| Easy Serviceability System |
The motor and screen surface of the projection screen are accessible for maintenance and service without uninstalling the screen casing. |
| Edge Blending |
A setup with multiple projectors projecting a single source creating a single image. |
| Gain |
Gain is a measure of reflection performance. Gain is related to a universal reference standard: Magnesium Carbonate (MgCO3). Rather than absorbing light, MgCO3 reflects projected light back with perfect evenness. |
| Ghosting / Crosstalk |
This describes the interference of one signal with another signal. It measures the amount of noise or the amount of left- eye signal seen by the right-eye. |
| Hot Spot |
A hot spot occurs when the light of the projector is centered on the projection screen creating a brighter area. Hot spotting is the opposite of uniform projection. |
| IP |
Internet Protocol is the most commonly used set of rules for dispatching data across a computer network. |
| IR: Infrared |
Wireless control via Infrared wavelengths are used to operate the projection screen. The receiver has to be placed into sight of the remote control. |
| Keystone Correction |
Distortion created by the angle of the projected image can be corrected by tilting the angle of the projection screen. |
| LUX |
Lux is the perceived amount of light that is reflected by the projection screen. |
| Lace and Grommet |
A projection screen that has a border with grommets. Grommets are reinforced holes which allow the screen surface to be attached to a frame. |
| Overall Dimensions |
The overall dimensions of a projection screen are the dimensions of the projection surface including the borders. |
| Passive 3D |
Passive 3D uses polarising filters and a projection surface with polarisation retention to separate the two different signals. Passive 3D is often realised using two projectors, one for each eye’s information. |
| Pincushion Distortion |
Image magnification increases with distance from the optical axis. This creates an image where lines do not go through the centre of an image but are bowed inwards towards the centre of the image. |
| Polarisation |
Polarisation is a property of certain types of waves that describes the orientation of their oscillations. These differences in orientation are used to project different signals. |
| Polarisation Retention |
Polarisation retention is the ability of the screen to maintain a certain polarity of incident light upon projection. This is the ability of the projection surface to retain the orientation of the signal and preserve the polarisation. |
| Potential Free Contacts |
Potential free contacts refer to a contact of a relay which does not make or break a current. Usually some other relay or device has the job of starting or stopping the current. |
| RAL |
RAL is a colour matching system used in Europe. |
| RF: Radio Frequency |
Wireless control via Radio Frequency is used to operate the projection screen. The receiver can be placed out of sight of the remote control. The range of RF is 20 metres through walls. |
| RS232 |
Recommended Standard 232 is a standard for serial binary data and control signals commonly used in computer serial ports. |
| Stereoscopic 3D |
The technique of creating depth in an image by using a separate image for each eye. ‘Stereo’ means two and ‘scopic’ means view, so Stereoscopic 3D uses two points of view with left and right eye distinction. |
| Tab-Tensioned |
Parabolic curves on both the left and right side enable a vinyl front or rear projection screen surface to be perfectly flat and retractable. The parabolic curves are calculated in relationship to the size of the screen. Tab-tensioning allows for the flattest possible projection screen surface in a retractable screen. |
| Uniformity |
An even distribution of light on a projection screen. Uniformity is essential for an even image with a wide viewing angle in the desired direction. |
| Viewing Angle |
The viewing angle of a projection screen fabric indicates the maximum angle at which the projected image is still clearly visible. |
| Viewing Area |
The viewing area of a projection screen is the available area for projection within the borders. |
