Ultra Low Cost Telescope Project

Question

A few years or so ago there was a project that distributed small very low cost telescopes (perhaps around US$20). What was the name of (and links to) that project?

Answer 1

If you're interested in a low cost, but usable telescope that provides decent performance, look into the Galileoscope.

http://galileoscope.org/

It provides 50 mm (2 in) of aperture, at a focal length of 500 mm - so it's an f/10 instrument.

The kit is very easy to assemble, and instructions are provided on the Internet in great detail. Even kids can assemble it, with some supervision.

The objective lens (the primary optics) is an achromat doublet - it's made of two actual lenses combined to reduce chromatic aberration. I was impressed by the quality of that lens, at least when compared to its price - it seems to work as well as optics in instruments that cost several times more. This is one of the main reasons why I recommend this instrument to beginners.

It uses standard 1.25" eyepieces. That means you can either use the eyepieces that come with the kit, or you could borrow any 1.25" eyepiece from another telescope and just use it. This is rare in an instrument this size.

The kit gives you the option to build either a galilean eyepiece, or a 2x barlow. My advice: don't bother with the galilean eyepiece; its field is far too narrow. Instead, build the 2x barlow.

There's another eyepiece in the kit, use it either alone or combined with the barlow.

In theory, the maximum magnification is 100x, but in practice things will get a bit difficult when you push magnification much over 50% of the max value. This is typical for many telescopes.

Important: Like any telescope used for astronomy, this scope will not work well if you just hold it with your hands. You must use some kind of mount. The scope comes with a standard mounting nut that fits any tripod used for photography or astronomy. Use the sturdiest, most rigid tripod you can find. Even a very little amount of wobble will make it very difficult for you to use the scope.

Alternatively, make and use a DIY mount such as this one (results will vary depending on skill and materials used):

https://aquillam.wordpress.com/2010/01/04/a-cheap-tripod-alternative/

At the very least, support one end of the telescope on a fixed, tall object such as a fence; this will make things a little better, but it's not a replacement for a true mount.