Selecting and buying the right telescope really boils on on your budget, what you plan on spending the most time viewing, and where you will using your telescope most at. With that said, below are some guidelines. Also see Types of Telescopes.
Telescope Rules of Thumb
- First telescope and on a budget? Choose a Dobsonian.
- Interested mostly in viewing the moon and planets? Buy a refractor.
- Interested in viewing galaxies, nebula, and star clusters? Buy the biggest reflector you can afford - this will be a Dobsonian.
- Concerned about portability and weight but want a good all-around telescope? Buy a Cassegrain.
- Want absolute quality and money is no object? Buy an apochromatic refractor.
- Serious about astrophotography? Buy an apochromatic refractor or astrograph reflector.
Do's for Buying Telescopes
- As a first telescope, a 6" or 8" Dobsonian reflector offers great bang for the buck. On the refractor side, an 80mm on a stable mount is also an OK alternative first telescope.
- Plan on spending a minimum of $300 for a decent beginner's telescope.
- Get an oversized/overrated mount - telescope mounts MUST be sturdy.
- Stick with 1.25" size eyepieces at a minimum, stay away from 0.965" designs.
- Get a size and weight that you don't mind setting up or lugging around to remote sites.
- Select 2 (or 3) quality eyepieces and a Barlow lens. Lower-cost good-quality eyepieces are Plössl eyepieces. The Orion planetary filter kit is also a great deal.
- Get a guide scope.
Don'ts for Buying Telescopes
- Don't buy a telescope from a department store, nature-science store or toy store. These are totally unsuited for astronomy and will end up unused or in the trash.
- Don't buy any telescope that costs less than $300.
- Stay away from 0.965" size eyepieces - 1.25" eyepieces are a minimum.
- Avoid getting so large and heavy of a telescope that you don't want to use or transport it around.
Find your inner astronomer. Your complete guide to amateur astronomy.