Bargain Telescopes - The Cheap Telescope Survival Guide

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The Cheap Telescope Survivors Guide

We've all seen these telescopes in a department store or toy store. They advertise 500 POWER or 700 POWER. I've even seen 1000 POWER advertised. With color pictures on the box (taken with Hubble - no doubt). In all practicality, these telescopes are pretty useless for most of astonomy. They typically come with a shaky mount, under-sized and over-powered eyepieces, useless long-tube 3x barlow lens and a poor quality finderscope.

Soon you'll discover that the high magnifications are useless, you don't see cool color views (as shown on the box), you can't find anything other than the moon and once you find the object in the sky it starts to move out of view almost immediately. The Telescope ends up frustrating you. You feel stupid and the tlescope is relegated to the closet.

You have acquired a 50-60mm refractor department store telescope. Maybe is was a gift. Maybe is was found in some dark attic, closet or garage. For whatever reason, you cannot take it back to the store. Here are some tips to help you get some use out of these telescopes.

Tips to survive a Cheap Telescope

Adjust your expectations
- You are not stupid. It is the telescope.
- You will never see color with a small aperture telescope. This isn't a problem with the telescope, rather with the human eye, which trades color detection for light sensitivity at night. You need a large aperture telescope to start to see color or use photography, which does not have the biological restriction.
- A typical rule-of-thumb is that a telescope is capable of about 50 power per inch of aperture. A 60mm (2.3 inches) telescope would be capable of about 115 power. The good news is that for planets and the moon, you only need to get between 100-200 power to see details.
- Even with larger telescopes, the resolution of the atmosphere is no better than 1/4 wave -- which means unless you are on a mountain top or the desert or someplace with really still air (what astronomers call "good seeing"), you probably will not get over 200-300 power.
Adjust the mount
- Tighten down the bolts and screws on the mount on a regular basis. Consider this maintenance. The purpose of a mount is to provide a stable platform and reduce vibrations in the optical system. All mount vibrate, but how quickly they stop is a measure of their usefulness.
- Setup the tripod on dirt or grass or sand. Avoid decks and sidewalks.
- Some people hand a small chain from the top of the tripod to aborb vibration.
- Some people put the feet of the tripod in coffee cans of sand to reduce vibration.
Upgrade you finderscope if possible
Upgrade your eyepieces
- Eyepieces come is three barrel sizes: 0.965", 1.25" and 2". 80% of the eyepiece market is the 1.25" format. The 2" format eyepieces are typically used for wide-field views on really big telescopes (8" aperture and up). What usually comes with a department store telescope is some cheap plastic 0.965" format eyepieces.
- Quality eyepieces in the 0.965" format are available but scarce and difficult to find.
- Upgrade your diagonal to a hybrid 0.965 to 1.25" diagonal. The diagonal is the 90 degree mirror piece that goes between the focuser and the eyepiece. This will allow you to purchase 1.25" eyepieces which are plentiful and come in various grades of quality and price.
- Upgrade your eyepieces to 1.25" format and purchase two or three of the best eyepieces you can afford. Try to get one for high power for the Moon and planets around 100-150 power and the lowest possible power for dim objects like star clusters and nebulae.
  
  To calculate power divide the focal length of the telescope (between 500mm-1000mm) by the focal length of the eyepiece (3mm-50mm) and that will give you the power for that telescope and that eyepiece.
Throw out or upgrade the long-tube barlow
- Typically a department store telescope come with a 3x long-tube barlow lens. A barlow is a optical multiplier that can usually be used with any eyepiece. These barlows are usually extremely poor quality and usually over magnifies the telescope into uselessness. Best to toss it.
- If you have upgraded the diagonal (See above) and want to use a barlow lens then get a short tube 1.25" 2x barlow lens. Be careful not to over magnify the telescope.

Other things you can do with your Cheap Telescope

Replace the diagonal with a hybrid 0.965 to 1.25" "Erecting Prism" and use the telescope as a spotting scope. An Erecting Prism is a diagonal which normalizes the view like a binocular or spotting scope. For daytime use do not exceed 60 power -- The "poor seeing" in the atmosphere will frustrate you.
Save you 60mm optical tube assembly until you buy a really, really good telescope and mount the 60mm piggy back style onto the new telescope and use the 60mm as a "guidescope" for astrophotography.
Repack the scope in the box, wrap it up in generic wrapping paper and keep it as an emergency gift, when you are caught short and found "giftless".

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