Understanding the Basic of Telescopes

By: Liza Click author's name for more of his/her articles

When entering a new area of science, we almost always find ourselves with a puzzling new technical term to understand before we converse with the specialists. This fact is certainly true in astronomy.

The terms of astronomy, both the terms that refer to the universe and terms that explain the tools of the trade, the most prevalent being the telescope. So to get us off of the basic, let’s identify some of the basic terms that pertain to telescopes to help you be able to talk to the telescope experts more intelligently.

The first area of specialization in telescopes is the types of telescopes. There are three basic designs of telescopes that most people use which are the Refractor telescope, Reflector telescope and the Schmidt Cassegrain telescope.

Refractor Telescope
The Refractor telescope uses a convex lens to focus the light on the eyepiece

Reflector Telescope
The reflector telescope has a concave lens which means it bends in. The telescope uses mirrors to focus the image that you eventually see.

Schmidt Cassegrain Telescope
The Schmidt Cassegrain telescope uses an involved system of mirrors to capture the image you want to see.

Binocular Telescope
A binocular telescope uses a set of telescopes mounted and synchronized so your view of the sky is 3 dimensions.

Those are the basic types of telescope. There are other terms referring to parts of the telescope or to the science on how the telescopes work:

Collimation
Collimation is a term for how well tuned the telescope is to give you a good clear image of what you are looking at. With a good collimation telescope, you are not getting a false image of the celestial body.

Aperture
Aperture is the term that refers to how big the lens of a telescope is. The aperture of the telescope lens is the key to how powerful a telescope is. Magnification has nothing to do with it, its all in the aperture.

Focuser
Focuser is the housing that keeps the eyepiece of the telescope, or what you will look through, in place. The focuser has to be stable and in good repair for you to have an image you can rely on.

Mount and Wedge
Mount and Wedge refer to the tripod of a telescope. The mount is the actual tripod and the wedge is the device that lets you attach the telescope to the mount.

Altazimuth Mount
An Altazimuth Mount refers to the tripod of the telescope that holds the telescope in place and makes it useful during a star gazing session. The altazimuth mount lets the telescope to move horizontally and vertically.

Coma
The coma is the blurry area on the outer rims of your view through the telescope. How big the coma is and to what extent it interferes with your viewing will have is important to the effectiveness of your telescope.

Planisphere
Planisphere is a detailed map of where everything is in the universe and how to find the star you wish to study by keying off of known stars.

Barlow
Barlow refers to a specialized type of lens that you can buy to enhance the magnification of your telescope.

These are just a few of the basic concepts of telescope operation. We deliberately picked the ones you have to know to discuss telescopes intelligently. But your education into the more complex aspects of astronomy and telescope design and operation will go on for as long as you are a lover of astronomy.