Image projector can be built in minutes

There’s a pretty good chance that you already have everything needed to make this image projector. We thought that yesterday’s video projector was simple, but this one makes it look like a super-computer in comparison. [Esrun] grabbed a flood light, some transparency film, and a common magnifying glass for use in his still-image project. This is more-or-less an overhead projector without the mirror, but we though it was worth sharing in hopes that it would spark your imagination and produce some other projector-oriented hacks.

The real tricks in this build are alignment and focal length. A single piece of lumber was used to help keep everything in a straight line, leaving just the vertical alignment to account for. In order to get the image in focus, [Esrun] had to do some testing for positioning the transparency film and the lens. In the end he added strips of velcro to the base to make the components easy to move. He plans to add an enclosure and change from an incandescent bulb over to a set of LEDs. We’d like to see the addition of a carousel that can house multiple transparency sheets. That or a side-scrolling roll to give it more of a film-strip feel.


  1. ys0 says:

    maybe if I put a transparent LCD instead of the slide, i could screen a video

  2. MS3FGX says:

    Oh dear…

  3. Ben Wright says:

    I already have a film projector. 2-1/2 stars

  4. Hirudinea says:

    No, no, no, don’t go with an LED light source, use a kerosene lamp, go real old school!

  5. macona says:

    Thats not lumber, thats a sustainable organic optical bio-rail.

  6. JJones says:

    You already featured the most basic projector I’ve ever seen:

    I’ve tried it myself and found it to be very cool… almost wish I had known about it when I was in India.. but then maybe I wouldn’t want to have seen what’s in the water there ( but the Ganges is holy water.. it’s purer than fire – yeah right )!
    I digress.. sorry ;)

  7. Don says:

    RE: Hey macona… “Thats not lumber, thats a sustainable organic optical bio-rail.” I’m still laughing at that one!:) And here I thought it was just a Board. Guess you really do learn somthin new every day;)

  8. Slacking says:

    @ys0 read my mind :)

  9. Nubie says:

    Heh, I remember my best friend and I doing this as teens. We had an Alicia Silverstone Batgirl slide from a fast food promotion.

    We used Silly putty to hold the slide to a wooden ruler, and a flashlight for light.

    Fantastic. At the time I was trying to make a projector with a TV, I made a few, including a wooden box that held a PC monitor facing up with some angle iron rails to hold a 5/8″ board with a fresnel page magnifier and a mirror, that way I could project onto the wall.

    Anybody with a reasonably bright screen can do this in a dark room, just face the screen toward a light wall, or tape some paper up, take a lens and move it until it focuses, then block all the light that doesn’t go through the lens.

    Bonus points for swapping the yoke polarity on a CRT so that the picture isn’t mirrored anymore.

    Optics are fun. (come to think of it I have an Apex 65″ TV in the front driveway, I need to use the rear-projection screen for something one of these days. It powers up but the image is very dim and washed out, I think it needs a Jungle Chip.)

  10. macona says:


    Forget the screen. Yank the giant fresnel lens out and start burning pavement!

  11. echodelta says:

    Second on smoking dirt. Save the whole optics of at least one tube with the silicone oil and all, then sub a plate glass for the CRT. Then you can make a short throw large format 3×5 inch LCD magic lantern. The oil is a slimy mess, but is an optical necessity. A syringe or turkey baster is needed, save the oil in the other two tubes.
    These back pro’s are a great optical hackers dream, get ‘em while there here.
    I saw a real magic lantern show once a few years ago, Victorian multimedia recreated with original era slides. With animated slides and dissolves, the story and music it was like TV.

  12. strider_mt2k says:

    I’d easily pay a nickle to take my sweetheart to one of these shows.
    Why, it’s positively keen!

  13. Whatnot says:

    Some case makers and portable HD makers use a simple led to project their logo on the floor/desk.
    I always thought that was a cute and simple idea.
    Might be interesting to use an arduino or something to select a LED and have each a different projection and then project messages based on external events.

  14. Erik Johnson says:

    @Hirudinea indeed! If you’re going to do a hack from 1646 (magic lantern), adding electricity would do it.

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