Living Room With a Projector
A projector turns the whole room into the equipment. Where the lens can sit, how dark the room gets at the hour you watch, and how far the screen wall is from the back of the room decide more than any specification will.
Plan from above
Three measurements
Room depth along the center line
Why it decides
It sets the range of lens distances available, and from that the range of throw ratios the room can accept.
How to take it
Run the tape from the screen wall straight back to the far wall, at roughly the height the lens will sit.
What it rules out
Every projector whose throw ratio, read from the manufacturer documentation, falls outside the range your depth allows.
Image width you actually want
Why it decides
Width, not diagonal, is what the throw calculation uses, and wanting a large picture is different from living with one.
How to take it
Mark the width on the wall with tape and leave it up for an evening before doing any arithmetic.
What it rules out
Any image size the room cannot light-control, and any size that runs into a door frame or a light switch.
Lens position to the nearest outlet
Why it decides
A projector needs power where it sits, and where it sits is rarely near the outlet that was put in for a television.
How to take it
Measure from each candidate lens position to the nearest socket, along the path a cord would actually take.
What it rules out
Any lens position whose cord would cross a walkway, and any position that would need a second strip to reach.
Room constraints
- Windows facing the screen wall put light exactly where the picture is.
- The lens position is often where somebody wants to sit, or exactly where people walk.
- A shelf has to be at the right height as well as the right distance, and most shelves are one or the other.
- No projector listed on this site states a throw ratio, so the model has to be checked against its own documentation.
- Sound no longer comes from the wall, which changes where the bar goes and what it is doing.
Order of work
- Tape the image width on the wallMark the width you want and live with it for an evening. This is the number the rest of the plan is built from.
- Measure the depth and list the lens positionsDepth along the center line, then every surface, shelf or ceiling point a projector could actually occupy, with its distance from the wall.
- Work out the throw ratio rangeFeed depth and image width into the throw calculator. The answer is a range, because more than one lens position exists.
- Check that range against the manufacturerLook up the throw ratio for the exact model in its own documentation. Nothing on this site can do this step for you.
- Solve light and power before buyingDecide how the windows get covered and where the cord runs. A projector in a bright room with a cord across a walkway is two problems, not one.
Safety boundary
Stop
Do not look into the lens of a running projector, and keep children away from the front of it. A projector on the ceiling is held by the ceiling, not by its bracket: if you cannot confirm what is above the surface, stop and bring in an installer. Keep the power cord out of walkways and never run it under a rug to hide it.