SEKAS Outreach
This is the personal opinion of Ben Harding, and other astronomers may well disagree!
Telescope prices have dropped significantly over the years, and what was once a dream is now really not too expensive. Therefore while Patrick Moore once advised that new astronomers buy good binoculars or at most a 3” refractor so as not to break the bank, something much bigger is now affordable. As a result, I would ask anyone considering their first telescope to consider the 8” Dobsonian. (8” = 200mm. But I’m old, so 8” it is.) At the time of writing (Spring 2018) an 8” Dobsonian costs a bit less than £300
An 8″ Dobsonian in the Wild!
The 8” Dob is easy to set up and very easy to use, just point and shoot, as it were. There’s no polar aligning, no electronics to set up. Nothing much to go wrong. In particular, children find this by far the easiest telescope to use. The wide aperture is sufficient to gather light from quite faint objects and make them visible. It is powerful enough to allow magnification of maybe 200X on the planets, and up to 400X on the Moon. But most things don’t need this level, and at 50X the Orion Nebula is magnificent, galaxies M81 & M82 are in the same field of view, double star Alberio is bright and colourful, and star cluster M15 looks like salt on black velvet.
There are advantages to electronic GO-TO telescopes to be sure. But they take some setting up, and you miss the crucial bit about having to learn the night sky. With a Dob you have to find your target. And if you can’t see it with the naked eye you’ll have to hunt it down – Hop East from Aldebaran in Taurus to directly below Elnath in Auriga, oh, that star must be Zeta Tauri… wait, YES! That’s M1, the Crab nebula, the remains of an exploded star, and I found it! (& the joy is, if you miss M1 the Crab you may well come across M35 in Gemini, a delightful star cluster that seems to our eyes to be joined up as if in ribbons of stars.)
There must be a downside? Well, there is. Dobsonians are simple, it’s all about the optics, not the mount. And at higher magnifications it can be tricky to follow the star as it moves across the eyepiece. And they aren’t designed for imaging (photography). Nonetheless, many people do in fact take great photos through their Dob. Often with just a phone camera. Mainly of the Moon & planets, because their brightness allows short exposures. For faint things you need long exposures and a complicated mount. But you won’t get one for £300…
So, if you can afford it, buy an 8” Dob. You’ll see from eBay that second hand ones are barely any cheaper, so if you really don’t like it you can be sure to sell it for a good price again. If £300 is too much, or an 8” is too big, smaller Dobsonians are available, including tabletop ones like the Heritage models. These are actually ok, especially for children. But be careful about the price, they seem to vary quite a lot for what is actually the same telescope.
Don’t believe me? Start a discussion on our Facebook page… Better still, come to The Langton or somewhere & try our Dobs, and our GoTos, and our Equatorials, and our refractors…
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