ALR stands for ambient light rejection. As its name suggests it discards light so that the image looks better.
In case you are curious this is the screen. No I am not selling it and I get no benefit from sharing this with you. https://www.crutchfield.com/S-GTFWWh5HNhI/p_651AR103ST/Elite-Screens-Aeon-AR103H-CLR3.html?XVINQ=BVP&XVVER=BDY1
The reason I am sharing this is because it is remarkable how well it works. It was difficult to setup but totally worth it.
Now why would I buy another screen that costs $900? Simple. It was part of the bundle that I originally ordered. I ordered the projector, and two screens. One was an external screen that is 120 inches, and the other was a higher quality screen that is 102 inches.
The entire cost was $1600. The projector by itself is around $600, and the outdoor screen is $180 now at B&H. So a cheap and poor quality screen. What I have been looking at the projector on was something that made it look washed out and too bright and fuzzy. Now it looks in my opinion better than my high quality computer screen.
How can I say that? Easy. It is not as sharp but the colors are more accurate and it is easier on my eyes. In addition because the projector is reflected light I don’t suffer the blue light reflection that can cause eye strain.
The documentation says it reflects 95% of ambient light. I believe that. It has a dark gray color and it looks amazing. I couldn’t believe it when I first saw the image. It felt like getting a whole new projector.
If you want to improve your projector experience get one of these screens and you will love it.