Overhead Projectors: The Object, The Myth, And The Legend

Overhead projector
You OHP.

Overhead projectors were all the rage back in the day. At high school from 1996-2001, whenever a teacher had to make a point they’d bust out an OHP.

It all seems from the Middle Ages now. Blasting some poorly scribbled content onto a wall of screen.

But that doesn’t mean the OHP has a special place in landfills across the world. Let’s celebrate their contribution to society right… NOW!

The OHP

Now it’s important to point out an OHP shouldn’t be confused with an old age pensioner (OAP).

The latter are useful for many things, but projecting images onto walls isn’t one of them. In fact, that would likely be a breach of human rights.

We all know OAPs begin 79% of their discourse with, “Back in my day…” And back in their day, there were many, many OHPs.

But what is the overhead projector? It’s an optical system. What it does, right, is a focusing lens projects light from a slide that’s all lit with magic.

That’s blasted onto a projection screen, where you’ll see the formation of images. There’s a knob (lol) for focus adjustment, too. That’s in case you need to zoom in really close to something.

Back in our day, the OHP was always in use during science lessons for some reason. Other teachers relied on them, of course.

But we have this overriding and bemusing image of our redheaded male science teacher teaching us GCSE kids about sex education with an OHP and a pen to represent the male “trouser snake” (as it were). Life sure is strange in England.

Fast Facts!

In case you’re drifting off in boredom due to the largely tedious nature of overhead projectors, here are some fast facts.

These are made all the more exciting due to the use of exclamation marks!

  • OHPs have been around since antiquity! Ancient projectors included the magic lantern, plus the steganorgraphic mirror was a close equivalent!
  • Edmund Becquerel (a physicist) developed the first OHP in 1853!
  • OHPs were also popular as Tel-E-Scores in the 1950s for bowling alleys!
  • American scientist Henry Morton described the OHP as a “vertical lantern” in 1880!
  • OHPs are an effective self-defence weapon – simply pick up and hurl at a vagabond to ensure personal security.
  • OHPs weren’t invited by Elvis Presley!

Now See Hear!

Of course the OHP is nothing without a transparency sheet. “They” make these out of cellulose acetate.

You then scribble stuff on them and stick them on the OHP, which transports the details into another realm (also known as a projection screen). Other uses for transparency sheets are:

  • Toilet paper (if you run out of the normal stuff).

That’s it, we can’t really think of anything else. Suggestions, please, idiot readers?

Projections

What does the future hold for the OHP? Well, we sat down over lunch and had a good, long, hard 10 minute think about it. Our ideas:

  • Ban all OHPs and have them all blasted into space with a super cannon.
  • Build OHP retirement homes to store them all in.
  • Start a revolution! Become the leader of the OHPs, rally them together, and start the Overhead Projector Wars! Storm the Houses of Parliament, Europe, and wherever else in your vile conquest to blast crude images onto walls across the world.
  • Use your old OHP as a door prop.
  • Just, like, throw it out back and let the vultures peck it to bits.

Okay that’s it, don’t expect us to write about these things again. All the best!

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