Expert: Paul Wagner - 12/9/2006

Question
Dear sir,

I am intreasted in purchasing a telescope for night sky observation, however i dont know where to begin.  Ideally i would like a telescope that is not too complicated, yet powerful enough to obsereve the moon and intrestng celestial bodies etc.  Looking on ebay there seems to be good telescopes priced as low as 50 pounds sterling. unfortunately I am not sure what I should be looking for with reference to apperture or reflecting or refracting scopes. If you could  generally guide me in the right direction with regard specifications then I will feel more confident in buying a telescope which I am happy with.
Any help will be greatly appreciated,

Yours Sincerely
Hiaran Hughes

Answer
Hi:  

Most amateurs focus on a couple of things to look at in the sky:  the moon and planets, and the nebulae and galaxies.  There is a difference.  The moon and planets are bright enough to be seen in just about any scope--so you can go for a smaller telescope and spend the money on really good optics for a clear picture.

But if you are interested in galaxies and nebulae, then you need a larger telescope, so that the mirror or lens can gather a lot more light.  For example, a 6 inch diameter mirror will collect FOUR times as much light as a 3 inch mirror.  That makes a huge difference.  

I think the best scope for an amateur, at least to start, is a reflector telescope with an aperture of something between 4.5 inches and 8 inches.  Any smaller than that, and you won't see as much as you would like.  Any larger, and they get so big that they are hard to take out to observe.  Don't spend the money on complicated mounts or computers---until you really know the sky, those things just eat up your money.

Of course, all of this depends on your nighttime skies.  If you live in a region with fairly dark skies, then go for the larger scope, because it will really make a difference.  If you live in downtown London, settle for a smaller scope, and be content with the planets most of the time.  

If you want a more in-depth answer, you might go to Orion Telescopes website.  They have an excellent explanation of what you pay for, and what you get when you buy a telescope.  Unless you really know what you are doing, I would avoid buying telescopes on ebay.

Paul Wagner