Teleprompter mirror mode: which flip does your rig need?
Glass reverses your text left-to-right, so the software has to reverse it first. Which setting for which rig — and what to do when your rig needs both.
A beam-splitter teleprompter reflects your screen once before it reaches your eye, which reverses the text left to right, so the prompter must mirror horizontally to cancel it. Use horizontal mirror for the standard rig with the phone or tablet lying flat beneath the glass; use vertical flip only for rigs that invert top to bottom; use neither when reading directly off a screen beside the lens. If a rig needs both at once, turn the device physically upside down and set the prompter back to normal.
If your script is appearing backwards on the glass, nothing is broken. That is what glass does, and the fix is one button — but there are two buttons that look like they might be the one, and the wrong one makes it worse in a way that is hard to diagnose while a crew waits.
Why the text reverses at all
A beam-splitter rig is a sheet of half-silvered glass at 45° in front of the lens. Your phone or tablet lies flat beneath it, screen pointing up. The glass reflects that screen towards your eye, and passes the scene through to the camera behind it — which is the whole trick, and the reason you can look down the lens and read at the same time.
The cost is the reflection. Your script is reflected exactly once before it reaches your eye, and a single reflection reverses left and right. So text sent to the screen the normal way arrives at your eye backwards.
Mirror mode reverses it in software first. Two reversals cancel, and you read it the right way round off the glass. The camera, which never sees the reflection, is unaffected.
Which setting, which rig
| Your setup | Setting | Why |
|---|---|---|
| Phone or tablet flat under beam-splitter glass | Mirror (horizontal) | The glass reverses left-to-right once; mirroring cancels it |
| Monitor mounted below glass on a studio rig | Mirror (horizontal) | Same optics, bigger |
| Phone propped beside or above the lens, read directly | Normal | No reflection in the path, so nothing to cancel |
| Laptop or second screen, read directly | Normal | As above |
| Hood or periscope rig that inverts top-to-bottom | Flip (vertical) | A second reflection in a different axis |
| A rig that comes out inverted both ways | Normal, device upside down | See below |
The first row is the overwhelmingly common case. If you bought a consumer teleprompter rig for a phone, you want Mirror, and you want nothing else.
Why vertical flip exists at all
Vertical flip looks redundant until you meet a rig that needs it, and then nothing else will do.
Some hood and periscope designs put a second mirror in the path, or fold the optics so the image arrives inverted top-to-bottom instead of left-to-right. Projection-based setups can do the same. It is not common, but it is not rare enough to leave the control out — which is why we ship both, and why most prompters that ship only one are quietly assuming you have the standard rig.
When a rig needs both
In LensCue, mirror and flip are mutually exclusive — you pick one. That is not a shortcut, it is geometry: flipping both ways at once is the same transformation as turning the device upside down.
So if your rig inverts in both axes, you do not need a third setting. Physically rotate the phone or tablet 180° in the cradle, and set the prompter back to Normal. The two cancel out and you read it straight. A setting that did the same thing in software would just be a second way to express a thing your hands can do in a second.
The ten-second test
Do not test with your script. Scripts start with words whose mirror images are plausible, and you will squint at it and convince yourself.
- Type a short, obviously-asymmetric word into the prompter. LENSCUE works. So does your own name.
- Set it up in the rig exactly as you will film, and look at the glass from where your head will actually be.
- If it reads left to right, you are right. If the letters are reversed, switch to Mirror. If it reads correctly but upside down, switch to Flip.
Check it through the real glass, from the real seat, before you record anything — not on the desk beside the rig. The whole question is about what the light does between the screen and your eye, and you cannot answer it from anywhere except where your eye is going to be.
One more thing that is not mirroring
If the text on the glass is faint, washed out, or ghosting, that is not a flip problem and no setting will fix it. That is a brightness-and-angle problem: a bright screen, a dark surround, and a hood over the glass. It is also the reason a prompter should be light text on black — a white page behind a script is a lamp pointed at the glass, and it will wash out the very thing you are trying to read. Ours is black, always, whatever your system theme says.
Mirror and flip are both in the bottom bar of the LensCue teleprompter, free and without an account — or press M to toggle mirroring while you read.