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.
Advanced Astrophotography Kit with 80mm APO
Currently there are 2 requests to borrow this.
A defective power tank has been replaced and the.kit will be available for loan as soon as an operational check is completed by the equipment manager.
This advanced astrophotography kit includes a Meade Series 6000 APO ED APO (apochromatic) 80mm refractor, a Celestron Advanced VX telescope mount, a ZWO ASI294MC Pro cooled camera with a reducer/flattener, and all the necessary cables and power supply. It comes with all the pertinent manuals to use the various gear. This astrophotography kit is designed for imaging deep sky objects by capable amateur astronomers. The borrower should understand how to align and use an equatorial mount and must supply a laptop computer to operate the camera.
The Meade Series 6000 80mm APO triplet refractor uses extra-low dispersion optical glass to provide excellent color correction, contrast, and sharpness.
Explore Scientific AR102mm Refractor
Currently there are 3 requests to borrow this.
The Explore Scientific AR Series telescopes are classic air-spaced, crown-and-flint, doublet achromatic f/6.5 refractors with a superior-class optical figure.
The Explore Scientific AR Series telescopes come with heavy-duty, high quality components, including a 2" dual-speed Crayford-style focuser, a one-piece 2" diagonal with 99% dielectric coatings, an 8 X 50 non-illuminated straight -thru finderscope and quick release bracket, and a cradle ring assembly with Vixen-style dovetail mount.
A Twilight I mount is included. The Twilight I is a light-to-medium-duty alt-azimuth mount and tripod designed to quickly and easily accept small to medium sized refractors. The adjustable angle head can be tilted forward or back at a 45° angle to allow more clearance for your telescope so you can point it straight up for viewing at the zenith. Slow-motion control cables are attached on the vertical and horizontal axes, and are easy to turn during the night.
Currently Unavailable
The following list of equipment is not available to members until we are able to replace or repair parts.
Celestron NexStar 102 Telescope
Note This item is being serviced and it is not available for check out.
This refractor telescope has good optics but is awaiting a new mount.
- High quality 102mm (4") refractor telescope with multi-coated glass optics..
- Set of 5 eyepieces
- StarPointer finderscope to help with alignment and accurately locating objects
- Includes erect image diagonal for terrestrial observing
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