Build or Buy a Telescope?

Jack Kramer

"You made that!?" It's an expression of surprise and admiration from other people who see a telescope that we've built ourselves. For us, it's a source of justifiable pride. But the proportion of amateur astronomers who are now making their own instruments is smaller than it was even ten or twenty years ago. Today there's an abundance of well-equipped and reasonably priced telescopes on the market that appear very attractive.

I like a comment by Geoff Gaherty of the Royal Astronomical Society of Canada: "While sometimes I feel nostalgia for the 'good old days', my hunch is that we're now living in what will some day be regarded as the golden age of telescope making. Never before has the amateur had the richness and variety of choice that they have today. It's always a shock for me to leaf through my Sky & Telescopes from the late '50s, and see how limited and expensive the choices were back then."

Is it worth the time and effort to build your own telescope then? As one who has made several telescopes and bought several, I have some opinions, which may or may not help you decide whether to become an ATM (Amateur Telescope Maker).

Here I'm thinking primarily of Newtonian reflectors on the now-common Dobsonian mountings. If you'll want a motor-driven mounting for imaging and/or a compact optical design, then you're probably looking at a complete telescope package from one of the major suppliers. Few of us have the optical know-how or machining capability to produce from scratch a technically sophisticated instrument. Of course, many Dobsonians now are equipped with "Dob-drivers" for hands-free observing.

You have to admire those who actually grind and polish their own mirrors. In some cases, homemade optics are superior to anything you could buy commercially. But those who grind such mirrors - "glass pushers" - didn't acquire their skill overnight. They've honed their abilities by making several mirrors over the years; in fact, mirror making often becomes an artful hobby in itself. While fewer amateurs are building their own telescopes, far fewer still are actually grinding their own mirrors. The requirements to produce an optically precise mirror are pretty daunting for many of us. Personally, I don't choose to even try it myself.

However, building a basic telescope isn't rocket science. What a lot of ATMs do is mostly telescope assembly. They make the tube, rocker box, and whatever components they can, then purchase the rest, including the all-important primary and secondary mirrors. Can you still save money by doing this? Certainly. Does it save a lot of money? That depends on how much of the other stuff you make yourself. If you assemble the scope almost entirely from commercially made components, you'll probably save very little. If you can make your own mirror cell and secondary holder, plus maybe a finder scope and/or focuser, then you'll start to save some real money. If financial considerations are an important factor, then seriously consider this avenue. In the future, you can always upgrade the components.

You can now get some very good components at quite reasonable prices, so there's an advantage to shopping around for a variety of commercial parts. You can pick and choose exactly what components you want and purchase the mirrors from one of the better vendors. If you've read the astronomy press reviews of different telescopes from Meade, Celestron, Orion and others, you've probably noted that there is seldom a clear winner in terms of quality and usability. A telescope will be better in one aspect, but not as good as another in some other respect. To meet their target prices, manufacturers have to make certain compromises. You may not save any money if you assemble a scope from top-quality optics and components, but overall you'll end up with a far superior instrument. This is one of the main reasons for making your own telescope. Naturally, you can also upgrade a commercially made telescope, and many are forced to do this if they bought a poorly designed commercial product.

Making your own telescope does require some rudimentary skill with tools. It's also an education in itself - a good hands-on introduction to basic optical and mechanical principles. But the Newtonian design is still a fairly easy instrument to build, and there's help available from many different reference sources. In fact, from personal experience, you don't even have to stick with a Dobsonian mount; a no-frills German equatorial mounting is well within the capability of the average basement mechanic.

The fact that a smaller proportion of amateur astronomers is now choosing to make their own telescopes simply reflects that you no longer have to make your own. There are so many more choices on the market now than in the past. Moreover, a lot of these commercially made products are relatively inexpensive. And today many people are opting for more sophisticated optical systems and mountings that put a lot of capability in a small package that often includes such niceties as digital setting circles or Go-To capability. This often implies the purchase of a commercially made product.

On top of all this, a persuasive argument can be made that if you were to place a value on your personal time, you would come out far better purchasing a complete telescope from one of the better vendors. Then too, what would you rather do - spend time putting together a telescope or getting out under the stars that much sooner with a complete package delivered to your door? Viewed in those terms, it's easy to see why telescope making is increasingly the province of only those who particularly enjoy tinkering and/or need to save some serious money.

There is always that nagging question by the first-time telescope builder: "Can I really make a telescope that will work?" No one can say for sure, but I like to recall that Noah's ark was built by an amateur, while the Titanic was built by professionals. In the real world, there are few commercial products that don't cut corners somewhere. If you want an uncompromising instrument with the best optics, components, and design, expect to pay top dollar for it...or make it yourself.

Beyond all the other considerations pro and con, there is one thing on which no one can place a price tag: the sense of satisfaction that comes when touring the universe with a telescope that you have made.or assembled.yourself.

Published in the October 2003 issue of the NightTimes