SCREEN KNOW-HOW
B A S I C S
Basics about the fabrics
If you want to present pictures or information to an audience, be it in the private or business sector, a perfect presentation is indispensable.
However, this can be achieved only if projec- tion device and screen match each other. A slide projector, e.g., needs a different screen than a beamer. Before purchasing a screen, you should therefore think carefully about the intended pur- pose.
In the private sector, different factors are decisive than when used in the business world. When used at home, the pure pleasure of wat- ching the presentation is in the foreground; when the screen is not required, it should be hidden unobtrusively. In the business area, a stable design to withstand daily use and versatile appli- cations is required.
Basics about brightness
In order to view a projected picture, the picture must have a certain brightness. This brightness, of course, depends on the light in the room, and the picture must be brighter than the surroun- ding light. It is also clear that in bright rooms, the pictures must be proportionately brighter than in dark rooms.
A decisive parameter of all projectors is their light intensity. For multimedia projectors, this intensity is measured in lumen, where the stan- dard of the American National Standard Institute (ANSI) is applied frequently.
The larger the projection surface, the lower the amount of light per surface unit since projec- tors – irrespective of the size of a picture – always produce the same amount of light.
part from light intensity, the contrast value is an essential factor which influences the quality of the projected image. The contrast value indicates the ability of a projector to reflect a scale of sha- des as wide as possible in their colour intensity from the darkest to the brightest shade as in real
life. A high contrast will produce a natural, vivid image.
Hence, luminous efficacy and contrast value must match the brightness of the ambient light and the characteristics of the projection screen to produce a perfect image.
The ratio between the brightness of the pro- jector and that of the projected image should be 5:1 as a minimum to achieve the best image qua- lity.
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