Let’s start with the basics.

Projector Knowledge Base
What You Need to Know About Projector Brightness

Projector brightness plays a key role when selecting a projection screen. Certain screen types—especially optical ALR (Ambient Light Rejection) screens—require a minimum brightness level to perform properly. If the projector is not bright enough, the image will appear dim and lack clarity, particularly in rooms with ambient light.

Tip: The brightness rating data from manufacturers are not always accurate. It is a common practice for manufacturers to overstate brightness ratings. It’s helpful to verify your projector’s actual brightness using trusted third-party sources.

External verification sites include ProjectorCentral and Mondo Projos, both of which provide verified brightness ratings for most projectors on the market.
What You Need to Know About Projector Throw Ratio

The throw ratio determines whether a projector is classified as UST (Ultra Short Throw) or Standard/Short Throw. This distinction is important when choosing an ALR screen:

  • UST Projectors project light from a very steep angle at the bottom of the screen. They require UST-specific ALR screens designed to reject ambient light from above and the sides, while accepting light projected from below.
  • Short/Standard Throw Projectors project light directly from in front of the screen. These projectors should be paired with front ALR screens, which reject ambient light from above, below, and sometimes from the sides—such as Fresnel ALR screens.

Using the wrong combination of projector and ALR screen may result in poor image quality, loss of brightness, or uneven lighting on the screen.

Tip: You can find your projector’s throw ratio in the user manual or the product specifications table on the manufacturer’s website.