Astronomy
The Good, Bad, and the Ugly Telescopes
You know where to find the bad telescopes.
Department stores and camera shops abound in bad telescopes. So where
do you find the good ones? In Astronomical Specialty shops and advertised
in Astronomy magazines. Caveat Emptor. Even these sources have
some low quality telescopes that should be avoided. Follow the rule I gave
you before, expressed below in mathematical form:
Where D = diameter of objective lens or mirror expressed in millimeters and...
F = The telescope's Focal Ratio or F: Number:
(D X F) / 5 <= (2 X D) is Good and
(D X F) / 5 > (2 X D) is bad
The best telescope for you is the one you build yourself, even if
it does not measure up to the telescope described here. That is because you will learn
to understand it far better than than the one that comes with an instruction manual.
