An Ambient Light Rejecting (ALR) screen is a type of projection screen designed to reject ambient light from all directions; this means it can reject the light that comes from above, below, or from the sides. ALR screens are typically used in rooms with high ambient light levels, and they are designed to improve the image quality in these conditions by rejecting the ambient light that can wash out the projected image.
Combining an ALR screen with today’s far brighter laser projectors makes a projection system a compelling solution in nearly any indoor environment. However, to be effective at rejecting ambient light, that ambient light can’t be coming from anywhere near the projector.
With a great ALR screen, a projector ceiling mounted 12 feet back from a 100” screen (typical), ambient light coming from either side of the screen will have minimal impact on how the projected image looks. However, if the windows are in the back of the room, behind the projector, the ALR screen will not be effective.
The same is true for room lights. Ceiling lights directly above the screen will be rejected, but if that light is closer to the projector, it can’t be.
Ultra short throw projectors cannot use an ALR screen designed for standard throw projectors, as those screens mistake the light from the projector as ambient light. This results in a completely washed-out image. So, if pairing an ultra-short throw projector with an ALR screen, you must choose one specifically designed for a UST projector.
There are different types of ALR screens available in the market; some of the most common include:
ALR-fabrics: ALR fabrics are special materials designed to reject ambient light. They are typically made from micro-louvered materials that scatter the light that hits the screen, which makes it harder for the ambient light to reach the viewer's eyes.
ALR-painted screens: These are screens that are painted with a special paint that is designed to reject ambient light. They are typically made from a special paint applied to the screen's surface, making it harder for the ambient light to reach the viewer's eyes.
ALR-layered screens: These are made from multiple layers of materials; each layer is designed to reject a specific type of ambient light. They are typically made from a combination of micro-louvered materials and special coatings that scatter the light that hits the screen, which makes it harder for the ambient light to reach the viewer's eyes.
Ambient light-rejecting screens in a bright environment can be game changers in many business and education environments. In today’s newer classrooms, more emphasis is being placed on having natural light – skylights where possible and more windows. ALR screens can make a huge difference in these environments.
In addition to classrooms, ALR screens are ideal for conference rooms, auditoriums, and museums – anywhere where lighting cannot be completely controlled and minimized. They can be a game changer in brighter rooms, because you don’t have to spend more for an ultra-high brightness projector.