I have some solid advice for you. This article is aimed at beginners and people who don't know much about telescopes.
Craigslist is wonderful. You can get some really great local deals using it. But it can be tricky to buy a telescope this way. There are a lot of things you have to consider other than price. In this article I will give you some solid advice that will help you to get a good deal and will help you avoid some common pitfalls.
If you don't know much about telescopes and have never owned one you should try to get some help from somebody that has some experience. Have that person look at the telescopes on craigslist. And if you move on to the next step of buying it you should bring that person with you to go look at it.
Don't commit to buying the telescope without first seeing it! Tell the seller that your intention is to come look at it, with the cash in hand, and buy it if it suitable.
- Don't hesitate to ask questions through the craigslist system. This can be fruitful sometimes. But often times the person selling the telescope doesn't known anything about it. But still worth a try. Telescopes are moderately durable and they can hang around in a basement or garage for decades. So the person who is selling it might not have been the person who used it or bought it. But it is worth a shot to ask questions.
Accessories - Often, when looking at a telescope you will be looking at the various functions and features of the telescope itself. But the performance of a telescope can be greatly affected by the various ancillary things that come with it. The eyepieces are first on the list! Does the telescope come with eyepieces? If so, how many? And what type? Are they labeled with the mm dimension on them?
This is a really good thing because the accessories surrounding a telescope can be expensive and having as many of them as possible will save you money later when you want to buy more stuff like variouis eyepieces.
Is it a good telescope?
Well, we can't say without seeing it and using it but we can follow some rules of thumb. First off, is it made by a reputable manufacturer? If the telescope is made by any of these companies you can trust that it was built with quality:
- Cave Optical
- Edmund Scientifics
There are others. So, if the telescope you are looking at is not on my list it doesn't necessarily mean it is not a quality telescope.
If you go to look at the telescope
Be sure to actually use it! Put an eyepiece in it and give it a try. Take it outside. Don't be bashful about it. You are giving up hard earned money and you want to know if the telescope does the one thing it is supposed to do!
Some General Indicators of Value:
These guidelines will help you determine some kind of a general idea as to what the telescopes value is when purchased new. If the craigslist ad tells you the make and model of the telescope you can google it or look it up on amazon to see if it is for sale new.
1. The size and type of the telescope itself.
This is the most important factor. The bigger the telescope, generally the more valuable and useful it is. But there are some differentiating factors. You have to think of them in two different categories. Reflectors and refractors. The cost of each of these types is significantly different. Refractors are much much more expensive per inch of aperture. For example, a four inch reflector could cost 100 to 200 dollars. A four inch refractor could cost between 500 and 1,000 dollars.
2. The type of mount
The type of mount is also an important factor in the value of a telescope. The least expensive mount type is something called an Alt-azimuth mount. The following picture shows you one. It is a simple mount that moves the telescope left-right and up-down. It is a simple setup and perfectly fine for beginner telescopes. A telescope like you see in the picture here has a 60mm primary lens and you probably shouldn't pay more than 25 dollars for it. If it is a Celestron or Meade it might be worthwhile to go a bit more than that.
You can see in the picture here a telescope with an equatorial mount. It seems a little bit strange and there is a heavy counterweight on it. It also moves in an unusual pattern. It doesn't simply go up-down left-right. It moves in circular motions that mimic the rotation of the earth. This type of mount is generally found on telescopes that are of a better quality because this type of mount is more complex and more expensive to manufacture. It is also much better for astronomy. Generally a telescope with this kind of mount will cost more than the previous alt-azimuth mount. This telescope in the picture (I own this one). Is a nice beginners telescope with an 80 mm primary lens. I paid 120 dollars for it new. So you could judge from there. Big things are the larger 80mm lens and the equatorial mount.
Dobsonian mount - This typeof mount is a very simple and inexpensive mount.
The circular part at the bottom is on the ground. That part and the two parts that go up to hold the telescope are the dobsonian mount. This is a large telescope but inexpensive because it is functional and easy to use. Not a lot of fancy frills on this telescope and it is easy to use. The prices generally are reasonable on these telescopes. An eight inch dobsonian will be maybe around 300-500 new. Where as an eight inch refractor would cost you several thousand dollars. Dobsonians are in a class of their own. If it is 4 or 5 inches you should be able to get it for around 50 dollars. If it is a six inch it probably ok to go as high as 100. If it is an eight inch then a higher price is expected.
This is a dobsonian available on amazon: SkyWatcher S11610 Traditional Dobsonian 8-Inch (White)
Things to look out for:
Telescopes are notorious for being left in a garage or attic for years or even decades. This can be good or it can be bad. It is good in that it hasn't seen a lot of use. And it is bad in that it potentially has collected a lot of dust and dirt. oor even rust. Look for indicators of it being in disrepair - things like dirt, dust and rust.
And look carefully at the tube of the telescope. Are there any dents or dings on it? That could be a very big deal particularly with a refractor telescope. Same goes for the dew shield on telescope. If it is dinged or dented it probably was dropped! It may be out of collimation or out of alignment. With some telescopes they can easily be re-collimated but you have to know how to do it.
If the ad says there are parts missing you should try to ascertain what those parts are and look them up to see if they can be cheaply replaced.