How to Make a Simple Telescope

Create your very own, totally manual Gallilean telescope!

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Cardboard Tubes
• Glue Guns
• Convex And Concave Telescope Lenses

1. Acquire a pair of lenses - a large convex lens and a small concave one. (Convex lenses are thicker in the center than at the edge; concave ones are thinner in the center.)

2. Find two cardboard tubes that will allow one to slide inside the other.

3. Figure out how far apart the lenses should be by looking through the smaller lens while holding the larger one out in front of you. When you can focus on an object in the distance, measure how far it is between the two lenses.

4. Double that measurement. The length of the two tubes should be about this long.

5. Fasten the larger lens on one end of the wider tube. Hot glue is good for this.

6. Mount the smaller lens at the opening of the smaller tube. This is the eyepiece.

7. Build a gasket from cardboard or Styrofoam if the tube opening is larger than the lens.

8. Make sure the lenses line up with each other. The centers should be in the centers of the tubes and the lenses should be parallel with each other.

Tips & Warnings

• Magnifying glasses are convex lenses.
• The best type of lenses are a low-power convex lens and a higher-powered concave one.
• Ask at an optical shop for discarded lenses.
• If you can't see anything or only pick up part of an object when looking through the telescope, check the lens alignment.
• Don't look at the sun through these lenses.

[mryanda]

on 8/14/2008 lol! lame

[mryanda]

on 8/14/2008 lol! lame!

on 8/8/2006 The best way to get convex lenses with very long, focal length (highest magnification) is to get some cheap reading glasses from the drug store. The lower the diopter strength, the higher the magnification will be. But keep in mind a longer focal length means a longer telescope, and the lower the field of view will be. A concave lens can be found in the viewfinder of an automatic or disposable camera.

on 11/22/2005 If you have made a telescope, but when you look through it is blurry, try adding a pinhole to a paper and then add it to the concave lenses.

on 11/22/2005 When convex lenses are seen through other convex lenses, the images are upside down. This is called a Newtonian telescope.