Introduction: Homemade Telescope

Here's my first Instructable on how to make a homemade telescope! It's simple and easy to make AND use.

I had found out that putting a magnifying and minimizing glass together gave the sort of effect that you have in telescopes. How?

I sat down and looked through both those types of glasses every way possible until I made that connection.

Then, I had a EUREKA moment and brought a couple cardboard tubes that were lying around and got to work.

This is pretty fun for for backyard use, like looking at the stars or moon from far away, or even just read off your friend's computer from a distance.

Heheh. It's definitely works indoors too.

Step 1: Materials:


  • Small magnifying glass (this is concave, so the middle is thinnest and the edges are thicker- opposite to your friendly average magnifying glass)
  • Big magnifying glass (this is convex, with the middle thickest compared to the edges like your everyday magnifying glass)
  • Cardboard tube (ex. from kitchen wrap or aluminum foil). Make sure it's about the size of your big glass's lens, so it'll fit.
  • Another long cardboard tube- but this one a teeny bit smaller in width so it can slide in and out of the tube from earlier.
  • Hot glue
  • Small cardboard
  • Scissors or craft knife for the small cardboard
  • Paint, paper, wrapping paper, anything to DECORATE!

Step 2: Check Out Your Glasses & Cut Tubes Accordingly

Looking through the smaller glass, place the bigger one far out in front of you so you're looking through both at the same time (make sure there's something in front of you to see or read). Bring the bigger glass closer and farther until whatever's in front of you becomes the clearest it can be. That's the focal point.

Consider how far apart the glasses are at the focal point. You want your tubes to be a bit longer than that, but not too long it's an awkward length and is too hard to find the focal point at the end when your telescope is finished.

Unless your front tube is longer than the distance between the two glasses, you don't need to cut it shorter, but it'll probably look nicer if it's not too awkward and long. I cut my front tube 23 cm long, and the back one 25 cm. That way, when I slide the back tube in all the way, a little sticks out, and it looks a bit nice, while when I stretch it out, it's a little longer than I would need to find the focal point, but at the same time isn't too long and very hard to slide around and find.

Step 3: *Optional* You May Color/wrap the Tubes Now (or You May Do It Last- Doesn't Matter)

If you want to paint the tubes or wrap them with the color paint or paper you want the telescope to be, you can do it now before you attach the magnifying glasses, if you find it easier.

You can do it after attaching the glasses too if it doesn't bother you or feel too hard.

I used a nice and shiny dark blue as the main color of the telescope. It brings out the nice spacey feel, I thought. I also used a light violet for the rims since I felt it fit the space- feel.

You can use a variety of colors to fit a theme too. For example, if you're planning to make this as a prop to a pirate costume or event of some sort, earthy colors such as greens and browns, or bright island colors such as light yellows and blues as bases will really make it fit the feel.

Step 4: *Optional* Carefully Remove the Handle From the Lens

This is optional, but if you have the proper tools, carefully saw off the handles from both lenses with a handsaw and smoothen the spot out. Since I don't have a saw, I didn't cut off the handles from mine, so I went straight to the next steps and attached them.

You're going to want all your limbs if you're planning to make this by the way!

Step 5: Attach the Big Glass

Wipe your both the lenses. You want to make sure they're clean before glueing them on, just to make your life easier!

Hot glue the big glass to the end of the wider tube. Try not to get any hot glue on your lens- you want it to be the clearest it can be.

Step 6: Attaching the Little Glass: Cardboard Donut

Since the tiny glass is noticeably tiny compared to your tubes' width, we're going to use the small cardboard to attach it to the tube.

Put the back cardboard tube (the slightly less wide one) on the small cardboard and trace it out. Then, center your tiny magnifying glass on the circle you drew and trace it out. Then, cut it out and you should have a cardboard donut.

If you want to decorate your telescope, it's probably best to decorate the donut bit now, especially if you have your handle on. You can decorate the rest of the telescope later, since these steps won't really make it harder to decorate later.

Step 7: Attaching the Little Glass: Gluing

Here's where you start attaching the small glass.

Hot glue your glass to the center of the donut, and hot glue the whole donut to the tube you used to trace last step.

Step 8: Decorating!

Here's the fun bit! Use colored paper, wrapping paper, or paint to paint your tubes if you haven't before. I used dark blue and purple colored paper to give a space-like feeling, like I said before.

Next, you can add a light sprinkle of glitter, or paper cut outs of stars, comets, planets, glittery rainbows of galaxies- anything else you'd like to personalize or make your telescope look cooler.

I covered the whole thing with dark blue colored paper, then did the rims with rings of violet paper. I also used orange, pink, and yellow construction paper to make planets, moons and stars. I also used I different colors of glitter glue such as red, sliver, gold, indigo, and magenta to make it shine.

I didn't use glitter glue on the second tube because I thought the glitter might rub off anyway whenever I slid the tube out or in after the glue dries. Instead, I traced out the lines and added some sparkle to the stars with some red, orange, and green color pencils. You can try whatever you want though- creativity has no limit.


All you have left to do is slide the second tube with the small glass into the back of the wider tube with the bigger glass. The tube inside should be nice and snug in there, but should slide out and in smoothly.

If the less wide tube is too unwide (whatever you call it :P) and slides around too freely and falls out, this is what I tried.

I used hot glue to make a C shape around the end of the wider tube. On the open end on the second tube, I used hot glue to make a square shape about the width of the C's open bit on the big tube.

That way, the small tube doesn't jiggle around freely in the bigger tube and fits snugly, slides in and out smoothly like a good telescope should, and I can open it easily when I want to clean the lenses.

Step 10: All Done!

Now you have your nifty rainbow of a spyglass!

You may now pretend to be a pirate, watch some stars, watch some birds, or anything else you may want to do (I'm not responsible for if you choose to spy on people or get hurt by the way :P).

Have a great day, and happy making!

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