by Michael Wright
Around the holidays, astronomers get asked by friends and family members about how to buy a first telescope. In fact, the club received just such a questions last week from someone whose interest was sparked by a visit to our observatory. I’ve put together this brief guide to help answer that question based on my research and experience.
Every experienced astronomer has an opinion about how to pick your first telescope. Here’s a sampling of some prominent ones:
Sky and Telescope Magazine
Astronomical Society of Las Cruses
Royal Astronomical Society of Canada
Universe Today – Fraser Cain
Joe Roberts: here and here
Weber State University
Jay Reynolds Freeman
In addition to the above opinions, here are my own:
- Before shelling out for a telescope, explore the night sky with your naked eyes and binoculars. Get outside and enjoy. Learn the constellations. This will test your enthusiasm for the hobby and give you a good introduction. If you still want a telescope after a couple of months, then go ahead.
- Find out what you will be able to see in a telescope. The color photographs in astronomy books and magazine and found all over the Internet are produced using long exposures and large observatory telescopes or the Hubble Space Telescope. Views through an amateur telescope are very different. Check out the sketches at Astronomy Sketch of the Day or the book Turn Left at Orion. The pictures are more representative of what you will actually see.
- Buy a reputable brand. Meade, Celestron and Orion are the big three companies for beginner scopes. This does not mean that other brands are bad. Some companies like Tele-Vue and Takahashi specialize in high-end scopes more suitable for experienced observers.
- Don’t buy a department store telescope. They are junk. If you’ve received one as a gift and cannot return it, Joe Roberts explains how to correct their problems. Save your money until you can afford a quality scope.
- Size counts. Buy the biggest aperture that you can afford.
- Make sure that the mount is sturdy and stable. A shaky mount will ruin the best optics.
- Consider portability. If you have to transport your scope, a smaller, lighter scope may be more appropriate because it will get used more. Also, available storage space may be a constraint. Dobsonian mounted reflectors are often recommended as first scopes; however, they are bulky and heavy. I elected to buy a Meade ETX-90 for my first scope because I did not have the storage space for a Dob.
- Include accessories in your budget because you are going to want eyepieces, filters, a finder, a cover, a dew shield, carrying cases, etc. that usually do not come with the scope.
- Consider buying used equipment. Often good used equipment can be bought economically from someone who has upgraded to a better scope and no longer needs their first scope. Astromart and Cloudy Nights run classified ads for amateur astronomers selling scopes. I bough both my scopes and many accessories from Astromart ads. Be sure to read their advice.
- Go to a star party and try out some scopes. Most astronomers will let you look through their scope and tell you all about it.
GOTO mounts (a.k.a computer controllers) deserve a special mention because they are controversial. Some feel that reliance on GOTO mounts prevents users from truly learning the night sky. They prefer that observers star hop to objects and thereby learn the layout of the sky. Others feel that the convenience of GOTO mounts allows users to enjoy the night sky faster and avoid frustration finding faint objects. Should you pay extra for the convenience of the GOTO, or should you spend the money on more aperture? The answer depends on your goals and needs.
So you decide to go slow and try using binoculars first. How do you choose a suitable pair? Binoculars are specified by magnification and objective size. For example, 7×50 binos have a 50mm objective lens (the big ones in front) and magnify seven times. Weight is the most important feature because you have to be able hold them steady. Also, the size of the objective lenses is important because bigger ones will gather more light and let you see fainter objects; however, bigger ones are heavier. You have to balance weight vs objective size. Magnification is secondary. 7×42, 7×50, 8×40, 8×45, 8×50 or something similar would be a good choice for astronomy. One other thing: make sure they have a focusing wheel. I once had a pair that had a lever for quick focusing. The lever made it difficult to get a good focus on stars and planets.
Highpoint Scientific, a NJ vendor, has pages for roof-prism and porro-prism binos. These pages will give you an idea of reputable brands, weights and prices. Also, you can hold some binos to see what would be a comfortable weight if you visit local sporting goods stores.
I hope this guide helps someone make the right choice this holiday season. If I missed something or you have other opinions, I invite you to improve this article by posting a comment.
Clear skies and warm evenings to enjoy them.