Q&A for How to Make a Telescope

You can increase the magnification power of the lenses, and also add a third or fourth lens.

You should not look at the Sun with a telescope, even for a second, as this could cause permanent blindness.

You have to insert one more lenses in between but by doing so the size or length of the telescope will be double or more than double what it is now.

No. Telescopes take in light from the object you are observing and do not need a built in light source.

It doesn't state the magnification power of the lenses/magnify glasses, but using this structure you can make a reasonably powerful telescope.

Yes, but it will be smaller. A paper towel roll that is empty would be best.

You can use the larger lens from a magnifying glass or shop at a specialty science store.

The lens. A whole magnifying glass is probably more commonly used, but a lens is much more more comfortable to hold.

None, as adding lenses between them changes the behavior of the light passing through. You could, however, make a telescope with theoretically infinite lenses, if they're spaced out properly. However, bear in mind that every lens you add reduces image quality, brightness, contrast, etc.

Get a bigger roll, then apply super glue on the edges of the lens and put it in. It should perfectly fit. Poke it in with a pencil if you need to.

For an astronomical telescope with two lenses, the max length would be the sum of the focal length of the two lenses. A bit of variation will not affect much. This length is known as the tube length.

Certainly not. You need a minimum of two - one for the eye piece and the other for the far end.

You will need a minimum of two magnifying glasses of distinct strengths or focal lengths.

You have to spend probably about $20-$40 for the lens and the tubes.

Before you even think about tubes, hold the stronger lens up to your eye, and then hold the weaker lens at arm's length. Move it to and fro until you see a sharp image of distant objects. Get someone else to measure the distance between the two lenses. That is the separation you need to use in the tubes.

Yes, you will need magnifying glasses of different strengths. If you use both of same strength, the scope won't work at all. The magnification factor depends on the focal lengths of the two lenses.

You should be able to find plenty of telescope lenses online using sites like Amazon. You may even be able to find specialty lens stores.

I've pulled a bunch of lenses out of an old projector, and am currently using little more than a cardboard tube I acquired from work and some duct tape to assemble it.

Somewhere between 200mm and 900mm. It all depends on how close you want the stars to appear.

Concave and convex mirrors could also be used. I'm currently trying to build one out of a large shaving mirror and a smaller mirror used for covering blind spots in vehicles.

You cannot use regular glass, since it wont have any effect on the magnification.

Just add more and more magnifying glass/lens until it reaches to the power that you wanted.

No, you can't use scissors instead of coping saw because only a cutting saw can make a small part in the cardboard.

It depends on how fast you do things but probably 20 to 30 minutes to make method 1.

You have to determine the focal lengths of the two lenses; just measure the distance at which they form a clear image. The total length of the telescope will be somewhere near the sum of the 2 focal lengths.

A telescope requires spherical lenses only. Glasses usually don't have perfectly spherical lenses, so are not advisable.

No, you will need a bigger and a better telescope for that. But you should be able to see the moon more closely.

You will need the magnifying glass, which you can get it in a stationery shop or order it online.

It depends on the focal lengths of your lenses. Normally, the distance between the lenses would approximate to the added focal lengths. For example, if you had 2 lenses of focal lengths 200mm and 400mm, then the distance between the lenses should be 600mm.

This is about how to make a refracting telescope, so you don't need mirror. You only need mirror when making a reflecting telescope.