A place for night sky enthusiasts
Although the internet can be a wonderful resource for first-time telescope makers, it can also be a source of great frustration. No matter what the topic, it’s possible to find completely contradictory advice. Far more dependable are good ol’ fashioned books — especially those that have stood the test of time.
Continue reading “Telescope-Making Books: The Good, the Bad, and the Unnecessary”
Low-magnification views of the night sky can be breathtaking. It’s only with low power that we can fully appreciate the splendor of the Pleiades, the foggy expanse of the Andromeda Galaxy, or the wispy filaments of the Veil Nebula. But if discussions on internet forums are anything to go by, there’s a lot of confusion out there about how magnification, field of view, and exit pupils relate to each other. And without understanding these factors, you might end up shortchanging your telescope’s low-power capabilities.
Continue reading “Exploring Low-Power Limits”
The Astroscan’s greatest strength is its bare-bones simplicity, which unfortunately also means it lacks adjustments for achieving optical alignment.
Edmund Scientific’s Astroscan has been around since 1976. Its enduring appeal is at least partly due to its no-muss-no-fuss simplicity. You plop it down in its base, put in an eyepiece, and you’re good to go. The optics come factory aligned, so you never have to worry about collimation. Unless, that is, the mirrors go out of alignment. And since the Astroscan doesn’t have adjustments to correct this malady, you’re stuck. But are you really?
Waiting for twilight’s end at the Table Mountain Star Party.
The summer star-party season is in full swing once again and it’s time to hit the road! As an editor for Sky & Telescope magazine, I’ve traveled to most major (and quite a few minor) star parties in North America. They’re fun events and tend to have a number of things in common. Here’s a rundown of my top ten star party perks.
Continue reading “Gary’s Top 10 Star Party Perks”
My dear fiend Lance Olkovick (a.k.a. Nanook of the North) observing Jupiter at dawn from Mt. Kobau with his 12½-inch f/5. The scope I’m building will be similar to this.
The nights are cooling down and the days becoming increasingly overcast and grey. That can mean only one thing: it’s Telescope Making Season again. And so, I’ve decided to tackle a project I’ve had in mind for some time now, namely, a rebuild of my 12¾-inch truss Dobsonian.
Continue reading “Telescope Making Diary: Week #1”
Day 8: Going Round in Circles
Routing the hole for the top of the mirror box.
Cutting neat, tidy circles in plywood. This is where a plunge router really shines. And make no mistake — building a Dobsonian means cutting circles. In the case of my scope’s design, the first ones are for the tube ring and for the flange at the back of the tube, where it mates with the mirror box.
Continue reading “Telescope Making Diary: Week #2”
Day 15: Side Bearings
A finished pair of side bearings. The slots will serve as simple handles once attached to the mirror box.
Sometimes what seems like it should be a quick and easy operation, turns out to be unexpectedly complex. Making the side bearings from my scope was one such a case.
Continue reading “Telescop Making Diary: Week #3”
Day 22: Completing the Upper Tube
The scope’s upper tube all done. The gloss-black finish is achieved with Monokote.
With the mirror box done, it was time to move on to the comparatively straight forward job of finishing up the top half of the scope. This consisted of two tasks: giving the cardboard tube a protective covering and attaching all the hardware.
Continue reading “Telescope Making Diary: Week #4”
What you need to know when it comes to optimizing your scope’s thermal behavior.
Generations of backyard astronomers have debated why, inch-for-inch, the performance of a high quality refractor usually edges out an equal-quality Newtonian reflector. This disparity is most apparent when viewing low-contrast planetary detail — the images in a good refractors often have a touch more snap to them. Is there some intrinsic shortcoming in the design of the Newtonian reflector that makes this inevitable?
Continue reading “Beat the Heat: Conquering Newtonian Reflector Thermals — Part 1”
Solving the thermal management puzzle can be as simple as adding a fan to cool your telescope’s primary mirror.
In Part 1 I described the cause and consequences of telescope thermals, now let’s see what can be done to cure, or minimize the problem.
Continue reading “Beat the Heat: Conquering Newtonian Reflector Thermals — Part 2”