The last thing to consider when choosing a screen is the screen surface type.
Every screen manufacturer has its own proprietary screen surfaces. It is best
to check with them to be sure that you are choosing the correct screen surface
for your projector and application. There are some general rules that apply
for all screen surfaces.
Screen reflectivity is measured by a dimensionless specification called gain.
Gain describes the directional light scattering properties of a screen relative
to a specific standard reference screen. A one (1) gain screen would be a screen
that matches the reference screen. A .8 gain screen would be a screen that is 80%
as reflective as the standard screen, while a 1.2 gain screen would be 20% more
reflective than the reference screen.
You might be tempted to purchase a higher gain screen, but there are some
trade-offs to consider. Purchasing a higher gain screen to increase brightness usually
means that you'll end up sacrificing the viewing angle of the screen.
The viewing angle of a screen is defined as the angle, measured from dead center
of the screen, at which point the screen loses half of its brightness
(50% brightness). If your viewing angle is too narrow, seating positions that
are not located at dead center of front of the screen will suffer. As a general
rule, the lower the gain screen, the better the viewing angle will be.
Another point to consider if you are thinking of using a higher gain screen is
how even the brightness will be across the screen. Higher gain screens "hot spot".
"Hot spotting" is where the center of the image is noticeably brighter than the
corners. When used in a home theater, a higher gain screen can give the image a
very uneven look.
The last thing to note is that some screens appear to have very sparkly finishes,
which can be distracting in bright scenes when used in home theaters.
Glass-beaded screens are notorious for this as well as some of the newer,
very high gain, screens.
Wir sprechen Deutsches
