SELECTING THE RIGHT SIZE PROJECTION SCREEN FOR MY EVENT
The following guideline should be helpful as a reference when determining the correct size projection screen for my event.
1. Audience Distance from Screen: For readability, neck and eye comfort, the 2 x 10 rule applies. No one should be seated closer to the screen than two times the screen height or further from the screen than 10 times the height of the screen. For example, if the screen is 8’ high, the first row is set at 16’ away from the screen. The last row should be no further way than 80’ away from the screen. This presumes your slides are created with a 24 point font – if these rules applied someone with 20:20 vision can your slides for a sustained period.
2. Projector Distance from Screen: The usual rule of thumb is to place the projector 1.5 times the width of the screen, away from the screen. Including a couple of feet for the projector and an ‘air gap’ to stop overheating is recommended. For example, if the screen is 10’ wide then the projector should be 17’ away from the screen. We recommend using a short throw projector which means you can significantly decrease distance required from the projector to the screen. For example, our short throw projector will produce a 150” image with only about 6’ distance to the screen. This really helps when you are limited on space or when you don’t want the presenter walking between the projector and the screen and want a rear-projection screen.
3. Screen Height off the Floor: The bottom of the screen should be about 4’ from the ground so that the audience can see the bottom of the screen over the person sitting in front of them. By this rule of thumb, an 18’ ballroom ceiling means the tallest screen (including set) you could use is 18’ – 5’ = 13’ as a practical matter, you don’t want the screen touching the ceiling, so a 12’ height screen is the max for this room.
4. Screen Size: The other way of working out the ideal screen size is to divide the distance from the screen to the last row of seating by 10. Use the resulting number for the ideal height of the screen. For example, if the distance from the screen to the last row of seating is 96 feet, 96 divided by 10 = 9.6 therefore the ideal screen height is 9’ high (SDTV screen size would be 12’ x 9’). If the ceiling height allows, and you are in between sizes, go up a size. A presentation is easier to read if it is a little too big versus too small.
PROJECTION SCREEN OPTIONS
Rear projection – The advantages of rear projection include tidiness, not blinding presenters and no technical equipment situated in the audience. There is a common myth that rear projection costs more, this is not true.
Front projection – Front projection enables the full length of the room to be used for seating - allowing for the stage set. With a choice of long throw lenses, the projection distance can be extremely flexible – possibly from a balcony or even a dedicated projection room.
Low ceiling or obstructed view? – Additional relay monitors or projection screens can be situated further back in the room, though delegates will generally focus on the presenter and stage.