The Hippo


Dec 6, 2019








Joseph Derek stands next to his homemade telescopes. Courtesy photo.

Look to the sky

To learn more about the New Hampshire Astronomical Society’s public skywatches, visit See for more about the Springfield Telescope Makers and Stellafane Convention and for the Amateur Telescope Makers of Boston.

Look into the skies
The art of amateaur telescope making

By Allie Ginwala

 What does it take to turn a casual interest into a hands-on hobby? For Hudson resident Joseph Derek, it all started with the astronomy magazines he bought for his kids. 

His interest was piqued enough that he bought a small telescope and joined the New Hampshire Astronomical Society. He was intrigued to find that some of the society members were building their own telescopes and decided to give it a try himself.
“It was a little bit of a learning process,” said Derek, who works in carpentry. 
Homemade telescopes don’t typically look like the ones you’ll find at a planetarium, since those are commercially built and made entirely with metal. Derek’s telescopes are a combination of wood and metal, which he said is easier to do on your own.
So far he’s made two telescopes: a 250-pound, 18-inch reflector on a Dobsonian mount and a 400-pound 12½-inch reflector on an equatorial mount. (The size of the scope denotes the diameter of the mirror.) 
“You can do a relatively easy [6-inch] telescope and take a few months,” he said. “It all depends on how much free time you have.”
He makes reflector telescopes, the same design as the Hubble, which is typical for the larger optics, but someone could elect to try another option if making an even smaller scope.
“If you’re doing ... a 3- or 4-inch you can do a refractor, which, rather than reflect light to a focus, it bends,” he said. 
Once you know what type and size of telescope to build, draw out the basic design, gather the materials and get started on the mirror, a key part in the process as it has to be ground, polished and shaped. Though certain skills may come in handy for larger models, Derek said little background is required to build smaller scopes.
“A good place to look at the different types amateurs have built is the Springfield Telescope Makers of Springfield, Vermont,” he said.  
The Springfield Telescope Makers is a group of over 100 members that reaches throughout New England and the mid-Atlantic states. Their clubhouse is the site for meetings as well as the Stellafane Convention, an annual gathering of amateur telescope makers.
“They [New Hampshire Astronomical Society members] go to it every year,” Derek said. “Usually it happens in August around the new moon and Perseid meteor shower.”
If a trip to the Vermont convention is too much for a budding telescope maker, there are plenty of YouTube tutorials and books that can help guide you.
“When I started, I was reading a book called How to Build Your Own Telescope,” he said. 
Derek embarked on this hobby as a way to see things in the night sky, from planets and galaxies to nebulae and star clusters. 
“The Andromeda galaxy is pretty neat to look at, and in the way of planets Jupiter and Saturn are pretty interesting,” he said. “They’re really easy to see, large enough that you get a lot of detail.”
Sometimes he’ll set up a scope at the end of his driveway so his neighbors can take a peek, or he lends his time to join in NHAS’s public skywatches. The society’s website has a calendar that shows when club members volunteer their time to show the public the moon, planets and stars.
“If you’re interested in astronomy, it’s probably great to become involved in a club,” Derek said. “It helps you to really glean a lot of information and it’s really inexpensive and you can actually use club scopes and other scopes and you don't have to purchase or build your own. That’s just an added part of the hobby.” 

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