Short throw vs ultra-short-throw vs standard
The three throw types by throw ratio — UST (below 0.4), short throw (0.4–1.0), standard (1.0–2.0) — and what each suits.
The three types are set by throw ratio: ultra-short-throw (UST) is below 0.4 and sits inches from the wall; short throw is 0.4–1.0 and sits a few feet back; standard (long) throw is roughly 1.0–2.0 and sits across the room. For a 100-inch screen that is under 3 ft, about 3–7 ft, and 7–15 ft respectively.
Throw type is just a band of throw ratios. UST projectors are laser TVs that live on a cabinet below the screen and need a special CLR screen. Standard projectors mount on the ceiling or back wall and are the cheapest. Short throw sits between the two — handy for tight rooms without going UST.
The three throw types compared (100-inch screen)
| Type | Throw ratio | 100″ screen | Models | Example |
|---|---|---|---|---|
| Ultra-short-throw (UST) | < 0.4 | 1.8 ft | 29 | Epson EpiqVision Ultra LS800 |
| Short throw | 0.4 – 1.0 | 5.1 ft | 13 | BenQ X500i |
| Standard / long throw | 1.0 – 2.0 | 10.9 ft | 68 | Epson Home Cinema 2350 |
Frequently asked questions
Related guides
What is throw ratio?
Throw ratio is the projection distance divided by the image width: throw ratio = distance ÷ width. A 1.5 throw ratio means the projector sits 1.5× the screen width away — so for a 100-inch 16:9 screen (87 inches wide), about 11 feet back. A lower ratio sits closer; a higher ratio needs more room.
GuidesALR vs CLR screens
The two are not grades of the same thing, they reject light arriving from different directions, and the right one is decided by where your projector sits. A **CLR** (ceiling-light-rejecting) screen has a horizontal sawtooth structure that only works with light coming from below — that is, from an ultra-short-throw projector on a cabinet. An **ALR** screen rejects light arriving off-axis and suits a short-throw or standard projector further back. Put a UST projector on an ALR screen and you get a washed-out hotspot. Of the 110 projectors we track, 29 are ultra-short-throw (throw ratio below 0.4) and need CLR; the other 81 do not. And the number on the box will not help you tell the materials apart: across our 24 screens, CLR runs 0.5–1.0 gain and ALR runs 0.8–1.65, so 9 of them — 38% — sit in the 0.8–1.0 band where both types exist.
GuidesProjector ceiling mount height
Mount the projector so its lens lines up with the top of the image when the projector has 0% offset (most do), then fine-tune with lens shift. A 100-inch 16:9 image is 49 inches (124 cm) tall, and the screen bottom usually sits 24-36 inches (60-90 cm) above the floor for seated eye level.
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