How Does a Teleprompter Work? Glass, Screens and Scrolling
Learn how beam-splitter glass reflects a script while a camera films through it, how presidential prompters differ, and what controls scrolling.
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A camera teleprompter reflects text from a screen onto partially reflective glass in front of the lens. The presenter reads the reflection while the camera films through the glass. Software moves the words; manual control, fixed scrolling, an operator or speech-following software can set the pace. A browser-only setup displays text directly on a nearby screen.
How can the speaker see words while the camera sees through?
A coated beam-splitter reflects the words toward the speaker while letting the camera see through the glass. A dark hood and careful positioning help keep reflections and the frame out of the shot.
The glass lets some light through, so its quality, angle and lighting affect both the reflection and the camera image. The software displays and scrolls the script on the screen below it.
Why does the script need mirror mode?
Mirror mode flips the text horizontally so the reflection reads normally. Some displays already flip the image, so turning mirroring on in the software too can make the words backward again. Display LEFT 123 RIGHT and check it through the glass.
Keep mirror off for direct viewing. Mirror mode flips the script itself. Duplicating your computer screen or flipping your webcam preview does something different.
Who controls scrolling speed?
- Manual movement: the reader or operator advances the text as needed.
- Fixed scrolling: a chosen rate moves text until paused or stopped.
- An operator controls the speed while listening to the speaker.
- Some apps listen to the words you say and scroll to keep up.
LilPrompter uses fixed scrolling. Optional start/stop/reset voice commands control playback; they do not track the script word by word. Its 0–10 speed is a control scale, not a words-per-minute measurement.
How do podium and browser setups differ?
A presidential-style system reflects text from floor monitors onto glass panels beside a lectern. There is no need for a camera behind the glass. With a browser prompter, you read directly from a screen near the camera, so you are looking slightly away from the lens.
Some rigs use a phone or tablet; others, including Elgato Prompter, include a built-in display. Equipment terminology helps distinguish the glass, display and controls before selecting a setup.
Frequently asked questions
Is teleprompter glass a normal mirror?
No. Teleprompter glass reflects the words while letting the camera film through it. A normal mirror blocks the camera’s view.
Do voice commands mean speech-following?
No. LilPrompter can listen for start, stop and reset commands. It does not follow the words you are reading or change its speed to match you.