How to mirror teleprompter text for beam-splitter glass

Prompter glass reflects the screen underneath it, so text that looks normal on the screen appears reversed to the reader. The fix is to mirror the text before it reaches the glass.

Why the text must be mirrored

A teleprompter rig puts a screen face-up under a sheet of beam-splitter glass set at 45°. The camera films through the glass, and the person on camera reads the reflection. A reflection reverses left and right, so the screen has to show the text mirrored for the reflection to read correctly.

One window for you, one mirrored for the glass

If you run the prompter yourself while someone else reads it, you want normal text on your screen and mirrored text on the rig. Zett Prompter does this with an output window:

1. Open your script and click Open output window.
2. Keep Mirror output switched on. Only the output window is mirrored, and your own window stays readable.
3. Move the output window onto the tablet or monitor under the glass, then press F or double-click it for full screen.
4. Control everything from your window. Play, speed and text size stay in sync.

Using a tablet in the rig

Most rigs hold a tablet. You can use it as a second display (Sidecar on Mac, or apps like Duet), or share just the output window to it with screen sharing. Share the output window only. If you share the whole screen, the tablet shows exactly what your screen shows, so it can't be mirrored differently.

When to flip the text upside down

Some rigs mount the screen at the top and reflect it downward. Then the text has to be flipped vertically as well. Turn on Flip output upside down next to the mirror switch.

Quick checklist

• Text reads correctly in the glass, not on the screen.
• Reading line sits at lens height.
• Text is big enough to read from the presenter's distance. Start large and lower it.
• The output window is in full screen so no browser bars show in the glass.

Ready to try it? Open the prompter and click Open output window.

Questions