celexon Fabric for Folding Frame Mobile Expert - 406 x 228cm - Rear projection

Format:
The projected image is output in a format (aspect ratio) specified by the projector. The format is also determined by the resolution of the projector (see also the entry "Resolution"). The screen format is usually selected on the basis of the format of the beamer image. The most common formats are 4:3, 16:9 and 16:10.

Visible surface:
The usable surface of a screen is the coated part of the cloth on which the image is projected. The frame and box width are always a few centimetres wider than the usable surface of the screen.

Visible surface:
The usable surface of a screen is the coated part of the cloth on which the image is projected. The frame and box width are always a few centimetres wider than the usable surface of the screen.

Leader:
The leader or offset is the part above the screen. This allows the upper vertical area of the fabric of a roller screen to be limited and freely determined within certain limits. The leading edge prevents the visible area of the screen from being set too high when a screen is positioned in rooms with high ceilings.

Gain factor:
The gain factor (or also called gain) is used to assess the reflection behaviour of screens and describes the light gain achieved in contrast to the brightness of the projector. A gain factor of 1.2 indicates that a screen reflects 1.2 times more in a given direction than a defined white standard surface. The gain factor is always given for the straight viewing angle of 0 degrees.

Hot spot:
A hot spot is a brightening in the centre of the image on a screen. These disturbing artefacts are created by the direct visibility of the projector lamp and only occur on screens with a very high gain factor (1.8 to 2.0).