Wednesday, July 9, 2008

Don't Buy a Telescope That Doesn't Fit

In my post What Can I See With My Telescope I talked about how much detail and what sort of objects you can see with different sizes of scope (the size being measured as how big the light collecting area of the telescope is, like how big the main mirror or lens at the front is.)

The big scopes give the best views. So why not just recommend everyone go out and buy as big a scope as they can afford?

-You have to be able to lift it.
-You have to be able to store it.
-It will probably have to fit in your car.
-You may not want to have to use a ladder to get to the eyepiece.

My recommendation for a first scope is usually a 6" telescope, though anything from about 4.5" to 8" can work. But before you buy any scope, find out its dimensions and weight. Then:

Figure out whether you can lift a bulky, unbalanced weight that weighs as much as the scope without injury or other safety problems. You may be able to lift it, but are you going to have to take it up and down stairs, for example?

Figure out where you're going to store it. Is the space big enough? Are you going to need anything extra to protect the telescope while it's stored? E.g. a cover or carrying case may be required to keep off dust, sunlight, or protect it from damage. What effect will that have on space requirements?

Will it fit in your car alongside whatever else you will be taking on observing sessions away from home? Plan on an ice chest, chairs, accessories box, a few books and magazines, the other people who'll be coming with you, sunscreen, possibly camping equipment and so on.

How high is the eyepiece from the ground? How wide is the range through which it moves? Will you be able to observe without a stepping stool or ladder? Will you have to bend over at an uncomfortable or painful angle? If you plan on observing while seated, will you be able to do so for objects in very different parts of the sky? Find out the measurements for the scope you're interested in (if they're not posted, check in to a forum for that manufacturer's telescopes and ask.) Then break out the tape measure and mock it up somehow to see how the scope measures up against you (and any other potential users of your scope.)

If you're going to need a step stool or ladder for the scope you want, make sure you plan space for it, too!