Projection Systems

Matching the screen to a projector and room is one of the more difficult things to get right. The first thing to realize is that published light output (lumen’s) and screen gain tend to be very optimistic for all, but a few high-end manufacturers. It is possible that your projector when setup for great color will only have one third of the light output published when the lamp is new. It will drop even lower after 1000 hours of use.

Key issues to consider with projection systems are:

  • Screen size versus projector light output versus screen gain
  • Minimizing ambient and artificial light levels
  • Dark furnishings to improve image contrast
  • Speakers may be distracting if they are too close to the screen on a non-acoustically transparent screen. Consider allowing at least 1 ft between right and left speakers and the side of screen. Dark colored speakers are also an advantage.
  • Significant spacing between the edge of the screen, ceiling and walls will improve image contrast.
  • Screen gain can help with contrast when the room is not optimal, but they will introduce problems with off-axis light output and possibly restrict projector location.
  • Projector light output drops the greater the throw ratio (projector distance/image width) to the lens minimum ratio
  • Placing the projector in front of the primary seat may be distracting if it leaks light.
  • Projectors can be noisy. The higher the light output generally the more noise will be a problem.
  • Masking systems can be used along with anamorphic lenses to eliminate black bars from non-16:9 aspect ratio material. These can add considerably to the cost of a system.
  • Fixed screen, retractable screen and/or acoustically transparent screen
  • High on/off contrast is more important for movies than sports.
  • Single chip DLP projectors may present a color flash during eye motion to some people. Be sure this does not bother you before purchasing one.

I would look at reviews on the projectors you are interested in or contact a consultant like myself and find out how bright they really are from the factory and then target 15 fL light level at your seating position for a new lamp. That way you should have a bright enough image at the end of lamp life. You may even want it brighter if sports are your main use.

If you want to place the speakers behind the screen your choices are much more limited and the design is more difficult. You must sit far enough back to not see the perforations or weave in the material. You must also have enough room between the speaker and screen to not cause sound interference. The area behind the screen should also be heavily treated with acoustically absorbent material in this case.

Screen materials I would give strong consideration to are Stewart Filmscreen StudioTek 100, Stewart Filmscreen StudioTek 130, Screen Innovations Solar HD 1.3, Carada Classic Cinema White, EliteScreens MaxWhite, Da-Lite High Power and SeyMourAV Centerstage XD. You can also use a painted wall or Wilsonart Designer White laminate if a manufactured screen is too expensive. More details on these are available from the manufacturer and my test report linked to at the right and here.

Use the AccuPel screen calculator linked to on the right to calculate how bright your projector will be with your screen. You must use actual projector lumen’s and screen gain though and not manufacturer rated ones to get a reasonable estimate of the light output.

It is best to verify these calculations after the projector is in place, by looking at screen samples and projecting on the wall to be sure you like the size.

This discussion is all related to front projection similar concerns are also true for a custom rear projection setup, but the materials and design limitations are even more complex.