At A Loss For Words? Try A Teleprompter

With everyone doing videos these days, you might want to up your narration game with a teleprompter. [Modern Hobbyist] can help. Since he does videos — like the one about the teleprompter below — we assume he built it out of his own need for the device. Actually, this is his second teleprompter. The first one was larger and not battery-powered, so this new version offers more portability. The camera shoots through the teleprompter screen so you can look right at the camera and still stay on script.

The project reuses some of the original teleprompter code, showing a text file via a Raspberry Pi. There’s also a control keyboard that lets you remotely control the scrolling speed. The real key to this project though is the 3D printed housing. Well, that and the reflective glass screen. Given that, you could do the actual text display in a number of ways.

Apparently, the portability of the build is limited somewhat by the weight of the camera. You could, of course, use something lighter or perhaps add some weight opposite to at least balance it a bit. The 3D printing files are on Thingiverse and the rest is on GitHub, so you can easily make changes if you want.

You would think we would see more teleprompter projects, and we do see some. We’ve also seen a hack to let you look through your laptop screen on video conferences.

24 thoughts on “At A Loss For Words? Try A Teleprompter

    1. On my prompter, which is similar, but made of foam styrene sheet in the form of a box, I mounted a tripod socket to the bottom of the housing at the point that is close enough to the CG to make it reasonably well balanced.

    1. To be fair, building a teleprompter isn’t much more than rigging up a way to hold a screen, camera, and a pane of glass in a proper orientation—so they aren’t wrong.
      I’d just build it out of scraps of wood so I didn’t have to wait ten hours for large prints to come out. I’ve noticed that sometimes a 3d printer is a way to spend all day just to avoid having to touch a saw or hammer for twenty minutes

      1. While I expect you are sometimes correct – if you have a hammer everything looks like nail afterall, I’d argue that sometimes its also the choice to allow for easy replication and design iteration! Along with it being the easy way for folks without a workshop to get what they want – the 3d printer and its feedstock are tiny compared to the shed/workshop space or at minimum large toolbox full of tools and the huge box of clamps (which can never contain enough clamps) required to do it via other methods…

        Not everyone has all the tools, and even if they do – Can you design and make in steel/wood/plastic raw stocks quicker than a printer, only often. But can you then make a second/third/fourth iteration exactly as you want it easily? Or can you then share the precise design you ended up with after all the fiddling and fetteling to get around the fact wood work precision is is a bit of a meme joke among machinist for a good reason – and its not only that woodworkers can’t hack precise work (tongue firmly in cheek there). On the other hand a half way decent 3d printer is really damn precise and repeatable.

        There is also the argument of final finish, a 3d print is in many cases ready to use right off the printer. In wood there is a good chance you will need a varnish, oil or paint to keep it from warping easily with moisture etc, that’s several hours of drying time right there… Along lots of sanding in the prep work to make sure it won’t be forever giving you splinters. In metal you will spend a great deal more energy with the hand tools or need some good machine tools, and working in plastic sheet stocks is often hell – many of the common ones are either really hard to work on without cracks appearing and shooting across the part from nowhere or are so so sticky its nearly impossible to saw through at all etc.

        Then there is the argument about material properties, sometimes the plastics you can easily print in are just a better choice for the final parts anyway, even when you are avoiding multi material print cunning and the complex geometries is basically impossible to get any other way. In which case…

          1. Don’t see how – the Phrase you object to is accurate and fair. Had it been made any other way it would have been the “the real key is the “method of construction/primary material” housing” and been perfectly accurate… Mentioning 3d printing alot, because 3d printing is so damn handy, and even sometimes the best possible method, so it gets used alot…

        1. Ever heard of a auto cad machine, which is programmable to reproduce templates exactly as the 1st.. So if you want 5000 units of the 1st unit, hey presto. Then you talk of 3d plastic parts which the printer produces – have you heard of plastic pollution in the oceans and seas.. Ooh there’s something satisfying about watching bits of heated plastic, being produced into the part you require.

          1. And who actually has the CNC machine type setup capable of producing heaps of parts subtractively – practically nobody, as those machines have to be vastly bulkier and better built than a 3d printer to function well, and actually require some small degree of operator comprehension to get good results, or as in the case of laser cutting limited to very thin sheets, and very limited in materials that can be safely worked.

            The subtractive operations are also a great method to generate way way way more waste than a 3d print – take a part that is 500x heavier than it will be at finish and remove all those chips, or take exactly the right amount of plastic and perhaps if the geometry requires it add some small quantity of waste support materials… Also I said make the next iteration exactly as you wanted it – not create the exact duplicate anyway, as the point was anything you make without the aid of a good machinist and tools or CNC platform is going to be very very difficult to make those tiny geometry tweaks to the next version reliably (if your precision requirements are to the nearest mm or so its not a big deal, but in many cases there are at least a few surfaces that have to be way way better than that) – and that goes something like quadruple if you are use a material like wood that is so very varied and prone to changing shape by its nature…

            Also just what does plastic pollution have to do with using 3d printing for the material you choose to make your project in – practically if not entirely NOTHING! Picking fault with 3d printing something on demand vs the millions of tonnes of plastic packaging used to ship everything else is rather bonkers… And if plastic is a good material for the project its likely the material you would work with 3d printed or not! So then see the point above about just how wasteful subtractive methods tend to be in comparison…

            I’ve got nothing against other methods, I tend towards hand tools and my lathe/mill over the 3d printer myself, as for much of what I want they are the best tool for the job in hand. But that doesn’t mean the 3d printer isn’t ever the best tool for the job! And if its the only tool you have that can do the job, even if its really not the most ideal tool you are going to use it…

        2. I have a small aluminum case I’ve stuffed with the essential tools – a saw, a plane, couple of clamps, a file, an eggbeater drill, etc. and a small bench vise I clamp on to a piece of wood. I literally put it across my knees, with a paper basket on the floor, and make stuff like that while watching television.

          You don’t need a shed full of tools if you just think about what you’re doing. You don’t start with a tree in the woods – you go to the hardware store and buy a stack of paint mixing sticks, re-purpose those, or get a cheap dollar store serving tray and rip it apart for materials. Cookie tins for metal, clothes hangers for wire… half the fun is figuring out what you can use to do what.

          1. Depends on what you are making – I too have a few smaller toolboxes that are at least a good starting point for doing x or y type task. But to actually work on a complete project they never have all the tools required, so off to the tool store I go and unless the project is tiny you need more space than sat on your knees..

            That sort of scale of project you can just do on your knees is the miniature war gaming, hobby train buildings type scale of project. Can’t do a bigger project there, heck my desk weighs more than I do, I don’t want that on my knees, and almost certainly you can’t do it all with those tools… Not saying your are wron gon the fun of figureing out how to get a result from the stuff you have, but sometimes that isn’t enough..

  1. The light from the LCD splashes light on the front element of the lens, adding glare, reducing contrast. Needs a baffle to prevent this.

    The LCD is polarized, and the reflecting glass is near the Brewster angle. The LCD must have the correct orientation to reflect off the glass. If you guess wrong, you get no reflection.

    The light from the LCD illuminates the underside of the top of the enclosure, and the camera sees that brightly lit underside in the reflection off the glass. Black or not, it’s still brightly lit. Needs baffles, and distance, and black velvet/vantablack.

    The glass does not appear to have anti-reflection coating on one surface: there will be two reflections (one from each surface. This will appear to the talent as double images, but will also give a ghost fringe image in the output video.

    Good effort though.

        1. Ordinary LCD screens allow a lot of light to pass through, even in the black regions. That’s especially true with smaller screens that don’t have dynamic backlighting. And it’s especially especially true with the typical small LCD screens that aren’t made specifically as high-contrast television screens. Amazon doesn’t publish the specs on the screen supplied by the company, but similar TFT-LCD screens have a contrast ratio of around 400:1.

          The only light an OLED emits comes from the active elements being displayed. It’s essentially an infinite contrast ratio display, so it produces the minimum amount of light spill possible for an ordinary backlit display.

          To get better you’d need to shine a focused light through a bare LCD screen, like a slide projector.

          1. All true, but when you have even just 10% of your pixels illuminated, like they would be when displaying text, the 400:1 contrast adds just 2% to the total light output and glare compared to an infinity:1 contrast display.

            Backlighting with collimated light is a great idea to send light only to the talking head. A slide projector uses a light cone to match the projector lens, so would still spill a lot of light, but I got what you meant.

    1. So, “it works well” isn’t good enough for you. Note, by the way, that the glass is square, so it wouldn’t have been a great deal of trouble to rotate it 90° if the polarization had been problematic. Also, please note that pretty much all commercial teleprompters have the camera lens close to the glass; backing the lens away far enough to baffle it to avoid light from the monitor would increase the size of mirror necessary to avoid edge cutoff in wide angle.

      1. If it works well enough for the OP, great. Good effort. But it can be better. Your competitor will be better.

        Note, by the way, that rotating the glass 90° won’t change the polarization problem. It’s the LCD polarizer that needs to have the correct orientation.

        1. There is not any point in making it ‘better’ if in use you can’t actually tell the difference…
          Seems like this setup is very very functional, and something very much like the default universal design for such things, making it ‘better’ is almost certainly more effort than its worth.

          1. Having built a teleprompter, I can tell you very definitely, that changing the polarization of the mirror (i.e., by rotating it 90°) will absolutely change your reflected screen brightness drastically. It’s the DIFFERENCE in polarization that counts.

  2. I had one of these 15 years ago, but it was for 3D gaming. The camera was another LCD screen and I wore polarized lenses.

    Worked pretty well actually. You can even use a mirror on your face and set the monitors at 90 to each other on a desk.

    NVidia used to have these modes in all the drivers, coincidentally they removed it from the 8800GTS silicon re-release, the one with powers of 2 RAM (IE not 320 or 640MB). Ironic because that’s when they started pushing “3d vision” and then killed the tinkerer market.

    I’ve still got the square of half-silvered “glass” around here somewhere. Use the silvered side first to make any unwanted reflections less.

  3. i want a teleprompter i can use IRL without sticking anything dumb on my head or taking more than 2 seconds to set up at a regular podium, and i don’t have any ideas other than like setting my laptop (which i’m reading off of) closer to my line of sight towards the audience


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