Equipment
Teleprompter Mirror Mode and Beam-Splitter Rigs Explained
A professional teleprompter puts the words directly in front of the lens, so you look straight down the camera while you read. It does this with a sheet of special glass, and that glass is why teleprompter apps have a mirror mode. Here's how the rig works and how to set one up.
How a beam-splitter teleprompter works
The camera sits behind a sheet of beam-splitter glass angled at about 45 degrees. A screen lies flat underneath, facing up. The glass is partly reflective: it reflects the screen towards you, while still letting most light through to the camera behind it. You see the text floating in front of the lens, and the camera sees you through the glass.
A hood or shroud around the glass blocks light from behind, which makes the reflection brighter and stops the room reflecting into the lens.
Why the text has to be mirrored
A reflection reverses left and right. Text shown normally on the screen reads backwards in the glass. Mirror mode flips the text horizontally first, so the reflection reads correctly.
- Horizontal mirroring is what almost every beam-splitter rig needs.
- Vertical flipping is needed when the screen sits above the glass, or is mounted the other way round, so the reflection would otherwise be upside down.
- Reading straight from a screen with no glass (a laptop under the webcam, for example) needs no mirroring at all.
Cueline has both: press M to mirror horizontally during a read, and turn on "Mirror by default" in Settings so every session starts mirrored. "Flip vertically" in Settings turns the text upside down for rigs that need it.
Setting up a rig with a tablet or monitor
- Mount the camera behind the glass, with the lens close to it and centred, so the edge of the hood isn't in frame.
- Lay the tablet or monitor flat under the glass, with the top of the screen towards the camera.
- Open the script, switch on mirror mode, and check the reflection from where you'll sit.
- Set the text large and the column narrow; the glass dims the image a little.
- Use a dark background with light text. Bright backgrounds reflect into the glass as a haze in your shot.
- Darken the room behind you, or add the hood, until the text is crisp.
Controlling the prompter hands-free
With the screen under glass, you can't tap it. Drive it from a keyboard or remote instead. Cueline's keyboard remote covers a whole session:
| Key | Action |
|---|---|
| Space | Play or pause (starts with a countdown) |
| ↑ / ↓ | Faster or slower |
| M | Mirror |
| V | Voice-tracking |
| R | Start or stop recording |
| F | Fullscreen |
| Home | Back to the top |
| Esc | Leave the prompter |
On Android, the Cueline app adds Bluetooth remotes, a floating overlay that reads over your camera app, and 4K recording, as a one-time Pro purchase.
No rig? Read close to the lens
Glass makes the best eye contact, but you can get close without it. Put the prompter window right under your webcam, narrow the column and sit a little further back. See how to read a teleprompter naturally for more on eye position.