Gary Seronik

I built my 12.75-inch Dob for less than $700 — much less than a comparable commercially made scope would have cost. But is making your own scope always a money saving proposition? That’s what inquireing minds (canine or otherwise) want to know.

For diehard ATMs, building telescopes is a way of life. But for others, the decision about whether or not to make a scope often hinges on economics. Will I save money building my own? The question shows up regularly in on-line forums and in my e-mail box. Before the emergence of a large-scale commercial telescope industry, the answer was a definite “yes!” But with the current abundance of low-cost, imported Dobs, and the increasing expense (and scarcity) of telescope-making supplies, it’s reasonable to wonder if it’s still possible to save a few bucks by going the home-made route. The prevailing conventional wisdom says “no,” but my own experiences suggest the answer isn’t as cut and dried as that.
Continue reading “Telescope Economics: To Build or To Buy?”

Any new telescope-making book is a big deal, but one that is both new and important is a huge deal. I believe that’s what we have here with the arrival of Albert Highe’s Portable Newtonian Telescopes. It’s a very satisfying, and detailed volume that covers a great deal of territory not explored in any other telescope-making book. What makes it “important,” in my view, is that it not only advances the state of the art, but also provides a wealth of information that will stand the test of time. Albert, and his publisher Willmann-Bell, are to be congratulated on producing such a fine and valuable addition to the ATM’s bookshelf.
Continue reading “A New Telescope-Making Book”

There’s no getting around the fact that collimating your reflector telescope (Dobsonian or otherwise) is much easier when the centre of the primary mirror is marked with a paper doughnut. Thankfully, these days a good number of commercially made telescopes come with their mirrors pre-marked. But if your scope isn’t so equipped, don’t worry — the procedure for adding a centre doughnut isn’t difficult. In fact, the hardest part might be convincing yourself that you can take out the primary mirror without inviting disaster.
Continue reading “Centre-Dotting Your Scope’s Primary Mirror”

Aligning the optics of your reflector telescope is crucial for optimal performance — all the more so if you have a telescope with a focal ratio of f/5 or less. A good tool can make the difference between successful collimation, and an exercise in frustration that encourages you to settle for “good enough.” But selecting the right tool can be more confusing than actually using it. On-line discussions offer a bewildering array of opinions and experiences — some of which posted by people who make and sell the products they (naturally enough) recommend. So what do you really need to collimate your scope?
Continue reading “Collimation Tools: What You Need and What You Don’t”