Current seeing: 

January 2010

Upgrading a small telescope

by David A. Fuller
Special thanks to Russell Publications

Here’s how to get the most out of a small, retail store refractor.

Most “retail store” type telescopes have beautiful pictures of planets or galaxies on them, the implication being that one look through the “575 POWER!!” telescope will magically reveal all of these wonders with a minimum of effort.

Unfortunately, that’s a long way from the truth. But you can see a lot with a small, simple telescope. The trick is in knowing how to maximize what you do have while still keeping the costs down.

Eyepieces

Fortunately, most of these scopes have decent objectives. They will generally come with two or three eyepieces. If yours has a 20mm or 25mm eyepiece (is should say that on the barrel), keep it. It’s probably useful, and decent. If the others have “H” or “R” on them, it will make a good paperweight

What to do: Many companies sell very good eyepieces called Plossls. These typically range in price from $30 to $50. If your eyepiece barrels are 1.25”, Orion Telescopes, Agena Astro, Owl Astronomy, Oceanside Photo and Telescope (OPT) and even Amazon.com will all have decent options.

For .965” Plossls that sometimes come with very inexpensive, or older, used telescopes from the 1960's - 1980's (and which is becoming a scarce eyepiece size), try Hands On Optics. They carry some .965" Plossls. Alternatively, you can find some .965" eyepiece options at Surplus Shed, although their smaller eyepiece options generally aren't as good as Plossls. But they are probably better than what came with your scope, too.

I recommend getting a 9mm or 10mm eyepiece of you have a 25mm one already. That, along with a good 2x magnification Barlow, will provide plenty of magnification and wide field options for most telescope focal lengths in the 600mm to 1000mm range. If you get a Barlow, avoid getting a 12mm eyepiece if you already have a 25mm one - you'll just wind up with the same magnification using the 25mm eyepiece and Barlow as you'd have with the 12mm. Get one that is longer (15mm or 16mm) or shorter (9mm or 10mm).

Mounts and tripods

Sadly, these are often the very worst part of these telescopes. If you are handy with wood, check out the website HomeBuilt Astronomy and look for the “Kid Peek Telescope” mount. I’ve built two of these for my kids, and they work wonderfully. There are also some other good frugal astronomy ideas there.

Optionally, you may be able to adapt a telescope to a good photographic tripod. For a bit more, try one of the alt-az mounts that Orion Telescopes offers. The stability and ease of pointing a telescope that these mounts offers will provide MANY years of rewarding night-sky observing. Shaky, rickety mounts on the other hand, are a recipe for a closet-bound scope. Don’t waste your money on a scope that gathers dust! Buy or make a mount that will get used often.

Finderscopes

If the objective lens (or mirror) is halfway good on an inexpensive retail store telescope, then the finderscope is likely a useless 5x24. You likely won’t see much in it, and it won’t help you find anything! One option is to replace the finderscope with a “red dot finder”, similar to a Daisy Red Dot BB gun sight. I find them a little difficult top use under my own light-polluted skies, but away from town, they work pretty well. Homebuiltastronomy.com shows you how to add one of these to your scope for all of about $10.00!

The other option is to upgrade to a decent 6x30 finder. Try Orion Telescopes or Agena Astro – these tend to cost around $40 or so, but being able to see - and find - what you’re looking for in the night sky is well worth it compared to letting that $100 telescope sit in a closet unused.

Yes, I know – you’re now looking at perhaps another $100 to upgrade a supposedly “complete” telescope. I'd be upset too. But which is better: A $200 investment that actually sees the night sky, or $100 that sits in a closet because it’s frustratingly difficult to use? Better to invest $200 than waste $100, right? If you have any questions, please feel free to email me. I’ll be happy to share any insight or help that I can – I’ve probably been in a similar situation, or at least be able to point you in the right direction. I like saving money too!!

Eyesonthesky.com

So with that, keep your eyes on the sky – you just might find something beautiful, interesting and thought provoking that you can share with others. If you have any questions or just want to share your experience, feel free to email me at

(Sorry, that's not a "click through" email link - but it reduces the spam in my inbox to zero this way.)

Download a PDF format full-sky map for the current month at Skymaps.com.

*         *         *         *         *

One last thing: Please be sure to turn off your outdoor lights, or if you must have an outdoor light on, be certain it is a full cut-off fixture, and the minimum wattage required. No sense in lighting the underside of planes at night - it just ruins the night sky for everyone else! Besides, doing so really will save you money on your electric bills. For more information about light pollution, please visit the International Dark Sky Association.