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.

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.

Celestron Echelon 16x70 Binoculars

Currently there are 1 requests to borrow this.

Celestron’s large-aperture Echelon series binoculars were designed for use in low light conditions. Whether you are long-range glassing across a field or valley, or gazing at the splendors of the Milky Way, a pair of Celestron Echelon binoculars will get the job done. With an exit pupil of 4.4 mm, these binoculars deliver an amazing amount of light allowing you to see the most detail possible.

With the next to highest magnification in the Echelon series, the 16x70 model offers great magnification for astronomy, and provides enough power to bring small subjects into view, even at long distances.

Celestron Echelon binoculars sport high quality 70 mm objective lenses made in Japan. Superior BaK-4 prisms were chosen for maximum contrast and sharpness, and all air-to-glass surfaces are multi-coated with Celestron’s proprietary XLT optical coatings—the same high transmission coatings used on our observatory-grade telescopes to increase contrast and resolution.

 

Explore Scientific AR102mm Refractor

Currently there are 1 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

All our equipment is in good condition!

Telescope Types

Types of telescopes

Copyright NIAAS, North Ireland Amatuer Astronomical Society

What are those numbers?

Types of telescopes

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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: