The Different Projector Screens Fabric
Selecting the right
projector screen fabric can seem very complicated, however the better you understand the purpose of a screen fabric, the easier it will be to decide what's right for you. Different screen fabrics are designed to handle different applications depending on the resolution of the media being used, the lighting conditions, the viewing angle of the audience and the sound distribution within the environment.
The most important place to start when selecting a screen fabric, are with the Gain and Viewing Angle of the fabric. There is a lot to know about each and how they affect each other (as gain increases viewing angle usually decreases). Having a basic understanding of these features prior to making your choice of a projector screen fabric, is the only way to ensure that you will make the most out of your equipment within the constraints of your environment.
Gain, is a measurement of a screen fabrics light reflectivity from the projection device, when the measurement is taken for light targeted and reflected perpendicular to the screen. A typical screen Gain of 1.0, means that all the light being directed at the screen is being reflecting back with the same brightness. Gain is however, directly affected by ambient light in the environment of the projected image. The brighter it is in a room(whether natural light from windows, or artificial light from bulbs), the greater the light being reflected will dissipate and wash out the image. Conversely, the less ambient light, the truer the image brightness will remain.
Gain greater than 1.0 - Means that the projection screen fabric is increasing the brightness of the projected image back to the audience.
Application - Higher Gain screen fabrics are typically used in environements with higher ambient light, where the light cannot be adequately dimmed or controlled. For example: large auditoriums, convention centers or office building with windows. They are also used when a projector is not powerful enough to create the adequate amount of brightness for the evironment.
Pros and Cons? - Since an images brightness is a very subjective opinion, increased brightness may or may not be positive or negative. That all depends on the personal preferences of each individual. Too much brightness, however does eventually lead to the negative effect of "hot spotting". Projector screen fabrics with higher Gain exhibit mirror-like properties, namely a bright "hot spot" in the screen an enlarged (and greatly blurred) reflection of the projector's lens.
Viewing angle is a measurement of the distance from the center of the screen at which you can still see the same quality image as from the viewing axis. For example, some projection screens reflect more light perpendicular to the screen and less light to the sides, making the screen appear much darker (and sometimes colors distorted) if the viewer is not in the "sweet spot" or in the optimal viewing angle of the screen.