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.
Keywords
You can narrow your search of our equipment library by selecting any one of the below keywords.
Advanced Astrophotography Basic Beginner Binoculars Camera Celestron Dobsonian Imager Intermediate Newtonian Orion Portable Reflector Refractor Schmidt Cassegrain
Available Immediately
All our equipment is currently on loan to other members.
Available Soon
Available Eventually
The following list of equipment is currently loaned out to a member, and may include other members waiting to also borrow.
Orion StarMax 127 EQ
Currently there are 1 requests to borrow this.
The StarMax 127 telescope is a Maksutov-Cassegrain design that folds a long focal length into a relatively short and easy to handle optical tube. The long focal length (1540mm) makes it easy to reach high magnification for observation of the moon and planets. The 127 mm aperature is large enough for nice views of brighter deep sky objects. Includes an adjustable tripod and equatorial mount with manual slow-motion controls.
Orion SkyQuest XT10g - Computerized GoTo Dobsonian
Currently there are 2 requests to borrow this.
The SkyQuest XT10g features GoTo pointing. It features a 254mm (10") aperture, 1200mm focal-length parabolic mirror (f/4.7).
Assembly is straightforward, but please note: This is a heavy and bulky telescope. The base is large and weighs nearly 40 lbs. The optical tube weighs 30 lbs and is about 12 inches in diameter by 48 inches long. It may require 2 people to lift it and a bigger vehicle to transport it. Handles on the Dobsonian base's front and side panels help to lift and carry the heavy base. Assembly is done by lifting the 30 lb. XT10g telescope optical tube into the Dobsonian base and locking it in place with a hand knob. A two-star alignment must be done to orient the telescope to the sky for GoTo operation.
Our Orion SkyQuest XT10g GoTo Dobsonian Loaner Package includes an EZ Finder II reflex sight, three high quality eyepieces, and several useful accessories. The 10" primary mirror is center-marked to make precise alignment of the optics (collimation) easier to achieve (a quick collimation cap. is provided in the loaner package).
Currently Unavailable
The following list of equipment is not available to members until we are able to replace or repair parts.
Celestron NexStar 114 SLT
Note This item is being serviced and it is not available for check out.
With the light-gathering power of an 114 mm aperture, the 114 SLT comes with a fully computerized hand control with a database of over 4,000 celestial objects. With its pre-assembled, adjustable steel tripod, the NexStar 114 SLT can be up and ready to use in a matter of minutes. The SkyAlign alignment technology and the included StarPointer Finderscope with a red LED, makes aligning a breeze. Compact and lightweight in design, this scope can produce images bright enough to reveal Messier objects and also works well for planetary viewing.
Telescope Types
What are those numbers?
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