How to Make Your Own Amateur Telescope

Make a simple telescope with cardboard tubes.

Making an amateur telescope is a relatively simple task that has fun and educational benefits. You can use amateur telescopes for many enjoyable tasks such as star-gazing and bird watching. A telescope uses two lenses to magnify distant objects, making them appear closer and allowing you to see finer detail at a distance. The large lens, or objective lens, is at the far end of the telescope. The second lens, or eyepiece, is located at the front of the telescope. With the proper materials, an amateur telescope can be used for years of exploration.

Things You'll Need

• 2 cardboard paper towel tubes
• Black acrylic paint
• Paintbrush
• Large convex lens
• Small convex lens
• Hot glue
• Corrugated cardboard

Instructions

1. Paint the inside and outside of your paper towel tubes black using your paintbrush. If you have a hard time covering the entire inner surface, try pouring the paint into the tubes, allowing it to slide down the insides. Allow your tubes to dry.

2. Affix your small convex lens directly inside the end of one tube. Secure the lens in place with your hot glue. If the lens is too small, cut a ring out of the corrugated cardboard to fill in the extra space.

3. Secure your large lens to the end of the second tube using your hot glue. Wait for the glue to dry completely.

4. Insert your tube containing the small lens into the second tube. Your lenses should be at opposite ends of the tubes, with the overlapping tube segments in the center.

5. Look through the tube, positioning your eye directly in front of the small lens. Aim the telescope at an object roughly 20 meters away.

6. Focus the amateur telescope by adjusting the distance that the tubes overlap.

Tips & Warnings

• An eyepiece lens can be used from a disposable camera.

• When securing your lenses, assure that the widest part of the lens is at the center of the tube.

• Do not use a telescope to observe the sun.

References

• Sidewalk Astronomers: Plans for Building a Sidewalk Telescope
• Telescopes and Astronomy: Build Your Own Telescopes
• San Francisco Sidewalk Astronomers: Building Telescopes