While recently shooting a bunch of PSA-style videos of Democratic candidates, I was faced with the problem of getting them to look natural while reading their prepared statements. Cue cards didn't look natural, so I decided to build a teleprompter so they could maintain "eye contact" with the camera.
First, I searched for a free teleprompter program. I found Prompt! 7.0, a low-cost software package with a very usable free version that allows scrolling reverse-text and white letters on a black background, which I'll explain. The download is available from http://www.movieclip.biz/prompt.html
(click on any of these images for a much larger detail view)
I took an old milk crate, turned it over so the opening was facing down. Then I cut out one full side, leaving about an inch of the frame along the bottom to give it structural strength. Then I cut about a 6-inch diameter hole opposite it, for the camera. I took black construction paper and covered every square inch of the crate except for the holes.
As you can probably guess, I'm fond of that blue painter's tape for projects like this, because it doesn't leave any glue behind and it's very easy to peel off and reuse it.
I found an old picture frame in my basement and took out the glass. I put some plastic framing (it's silver here) around the glass to cover the sharp edges. Then I mounted the glass inside the box at a 45-degree angle. It's good to mount it in a way that allows you to adjust the angle slightly for fine tuning. The framing around the glass is just big enough inside the box to hold in place with friction, but I'm sure it's easy enough to come up with a reasonable mount if needed. This view is looking into the teleprompter from the actor's side, and the white square is the camera hole in the back. You can see the glass in it's frame inside the crate.
Run the Prompt! software on a computer. You can edit your text in it's built-in basic text editor. Once you're done, you can run the text reverse-image. (Update: I found out how to extend the text box to the bottom of the display, now it shows a full page of text)
We hooked up a separate flat screen and laid it on the table top. That way, we can watch and control the scrolling speed on the notebook while the flat screen is dedicated to the teleprompter.
The top of the flat screen is oriented towards your subject, so the glass that will be above it at the 45-degree angle will properly reflect and display the text. That's why you need to have the text in reverse-image in the flat screen, so it's readable when reflected in the glass.
Carefully place the box over the flat screen. You might have to change the angle of the box or the glass in order for your actor to read it. You also have to raise it up so they can read it easily. Position the camera through the hole in the back, and try to use black construction paper to matte out any places where light can get in around the lens.
Here's what the person sees. I left a little space around the camera to demonstrate where it is, but it works best when you block all the light from coming through.
Once you set the camera, you need to matte out any space around it where light might leak in, so your subject can read the reflected text easily.
This is the view through the camera hole with text projected on the screen. Because your set is lit so brightly, the text is too faint for the camera to pick up. But your actor can read the lines easily because the box is so dark.
Here I am using the cursor keys to vary the scrolling speed of the text. It's a bit of a trick to read along with the person talking when all the type is backwards. But the text is so big, you can pretty much follow along.
This was a fun little project, and it works surprisingly well. Many of our candidates aren't professional speakers, but their videos look great and we usually got it done in a couple of takes. Here's an example: