Anybody looking to purchase an overhead projector might be better off learning how to make an overhead projector, instead. They’re not too difficult to make, but they can make for a blurry projection experience if not made correctly. These aren’t the best projectors on the market, but they get the job done. If you need a better model of projector, try slide projectors or LED projectors with the right amount of lux.
While slide projectors, LED projectors, and similar models are great options, they can be expensive. A DIY overhead projector will get the job done if you just need to create an enlarged image to trace over. This won’t be the brightest projector you’ve ever used. For bright projection, ask yourself, “What is an HD projector?”
Creating the almighty projector at home can save you from buying an expensive product. A few basic types of projectors are available, which might make you question, “What is a projector, anyway?”
If you don’t have the time to build your DIY projector, consider buying a cheap, entry-level projector instead.
Print your source image onto your printable transparencies. You can use professional copy services for this or use the correct type of printer for the transparency sheet you have. This will need to be a backward, mirror image to work.
If you’re using blank overhead projector sheets instead, write in a larger font size than you usually would. You’ll need to write it as dark as possible for the projection of an exact image.
Cut a hole in one of the sides of your cardboard box. Then tape your mirror image to that side. Ensure that this is what is facing toward the white wall you’re projecting on.
Now, cut a small hole in the other side of the box. This will be an avenue for light to project on the overhead projector sheets. Light bulbs and smartphone flashlights are excellent choices for white light. No matter what white light you choose, make sure it’s a bright light, as well.
Turn off all sources of ambient light. Homemade projectors don’t emit the same brilliant light that even the cheaper projectors you can buy can. Dark rooms make for brighter images and allow the creation of a clearer image.
Your projector is ready to use. While it won’t work the same way as slide projectors, LCD projectors, or LED projectors, it should do what you need. Most people use them as digital art projectors, tracing images to create murals on a white wall.
How do I make overhead transparency sheets?
There are two options to create transparency sheets. The first is to use a computer to design your presentation and print it out using transparency film. You can also manually write or draw on transparency film.
What pens are okay to use on overhead transparency sheets?
There is spirit- and water-based pens available. Water-based versions will wipe clean with a damp cloth, but spirit-based pens require methylated spirits to clean.
Do printers exist for printing on transparency sheets?
Yes, you have a few print options with different kinds of printers. You’ll be best off purchasing an inkjet printer. Ensure that your printable transparencies are compatible with your printer model.
STAT: The use of transparent sheets for overhead projection, called viewfoils or viewgraphs, was largely developed in the United States. (source)