Projector Placement, Throw Distance and Lens Choice
The one formula
Throw ratio = throw distance ÷ image width
Turn it around to find distance: throw distance = throw ratio × image width. Example: a 20-foot-wide image from a lens with a 1.5 throw ratio puts the projector about 30 feet from the surface.
Measuring
- Image width: the width you want the picture to fill, not the whole wall.
- Throw distance: from where the projector can actually be mounted (booth, catwalk, front-of-house pipe, truss, or behind the screen) to the surface.
- Height: how high the projector sits relative to the image. Lens shift moves the image without tilting the projector, within limits.
Lens types
- Ultra short throw (fixed ratio, about 0.35 on Epson's UST lenses): sits a few feet from the screen; large image with fewer shadows.
- Short-throw and standard zoom lenses: cover a range of distances, so you have flexibility in placement.
- Long-throw zoom: for booths far from the stage.
Use the throw distance calculator to see which Epson Pro Series lenses fit your room. Throw ratios come from the manufacturer's published lens data, and results are planning estimates; lens shift, aspect ratio and mounting hardware all affect final placement.
Which lenses fit my projector?
Lens compatibility depends on the exact projector model. Check the lens product page, or tell us the projector model and we'll confirm. See Choosing a projector lens.
Still need help?
Send rough measurements and a photo and we'll pick the lens. Call us at 718-874-2642 or email hello@shopstagegear.com. You will reach people who work in theatre. See How to contact Stage Gear support for what to include so we can help faster.