Which projection screen is the right one?

Differences between video projection screens

Either for home cinema purposes or professional studio set ups, a beamer projects a light image onto a surface. In most cases there is a video projection screen used as a projection surface. The most important parameters when choosing the screen size is the capacity of the beamer (projection intensity) as well as the distance screen to beamer. Disregarding any dimensional limitations like the room size, also the available budgets and the viewer setup are playing an important role. Viewer setup means the position of the viewer in front of the screen, it has to be considered that not every viewer will be positioned in the perfect right angle to the screen. The viewer perceives the light reflected from the projection surface and the reflected amount of light should be as consistent as possible over the whole screen. The light density factor, also called gain factor, is referred to the reflexion behaviour of the screen.
 
What’s the gain factor?

The gain factor indicates the light reflecting behaviour of the projection screen referred to a certain angle. The ideal projection and viewing angle is 90° to the projection surface. A viewer sitting in front of the screen with an angle of 0° has the ideal position. But not every viewer can be positioned in the perfect angle area. That’s where the important role of the gain factor comes in. With a viewing angle of +/- 20° from the ideal angle, the gain factor should be around 1,2. Projection screens with a gain factor of 1,0 provide a good image for angles up to +/- 50°. The reflection of the available light to both sides increases using screens with a gain factor below 1,0 with a maximal possible viewing angle of +/- 80° using a gain factor of 0,7.


What should I consider when buying a video projection screen?

Further quality parameters of screens are their characteristics like the granulation of the coating. It is also very important to avoid wrinkling or staining. Usually high quality screens have a higher durability and are easier to maintain. To choose the ideal professional screen it is recommended to ask the advice of an expert. The most expensive screens are not necessarily the best choice for any purpose. The quality of the screen material though should meet the requirements. Often attractive package deals turn out to come with low quality screen material, sometimes even made of paper. Besides the gain factor of the surrounding area, the right size and format are to be considered. The screen material should be flame-resistant. Most screens are made of laminated paper, PVC or diverse fabrics. For high quality materials even glass-fibre fabrics are used. Materials with several layers can be up to 100% lightproof. Please mind here to check the quality of edges. A washable surface guarantees an easy cleaning ofthe screen with commercially available mild cleaning agents. Of course high-end materials are pricier, but in many cases they guarantee the viewer to enjoy a cinema feeling without compromises. In addition to the budget, also individual factors like the room should be the key parameters for the purchase of a projection screen.

For home cinema purposes, many factors play a role. That’s why it is so important that everything is correctly adapted to the individual scenario. The ideal screen has a good reflection behaviour, is easy to clean and is light-dense.