Equipment Library

The Seattle Astronomical Society maintains a library of small and medium size telescopes that may be checked out for a period of 1 month by members in good standing. If you are new to astronomy, this is an excellent way to learn how to use a telescope and to begin viewing the wonders of the night sky, without having to invest immediately in a telescope of your own. To check out a telescope, please check out our equipment available for loan.

If you have any questions about borrowing equipment, or do not see a specific piece of equipment please reach out to our Equipment Manager.

See the complete equipment list in alphabetical order.

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Keywords

You can narrow your search of our equipment library by selecting any one of the below keywords.

Astrophotography Basic Binoculars Camera Dobsonian Go To Go To Maksutov Newtonian Push To Reflector Refractor Schmidt Cassegrain Visual

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All our equipment is currently on loan to other members.

None of our equipment is loaned out to any members.

Currently Unavailable

The following list of equipment is not available to members until we are able to replace or repair parts.

Meade ETX-125 #2

Details

Maksutov Go To Visual

Note This item is being serviced and it is not available for check out.

Special Item-Contact the Equipment Manager to Borrow this telescope

This telescope was recently acquired by SAS and is not yet ready to be loaned out. It is the second of two simialr ETX-125 telescopes in the Lending Library.

Telescope Types

Types of telescopes

What are those numbers?

Types of telescopes

The f-ratio is the focal length divided by the diameter of the telescope. Magnification is the focal length of the telescope divided by the focal length of the eyepiece.

Example

To find the f-ratio of a telescope 10 " in diameter with a 45" focal length:

Divide 45 " F.L. by10" D. to get an f-ratio of 4.5.

Compute Magnification

First, convert focal length to mm: 45" = 1146 mm, then:

1146 mm focal length divided by 35 mm eyepiece equals 33 magnification.

More Information

If you are interested in learning more about telescopes, we recommend:

SAS member Sorin (aka Soggy Astronomer ) has written an article, The Agony of Buying Your First Telescope and also presented at our May 15, 2013 general meeting, which includes additional information and links.
Sky & Telescope's excellent article on equipment basics
North Ireland's Choosing A Telescope by Andrew Johnston