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.

Keywords

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

Astrophotography Binoculars Camera Maksutov Newtonian Refractor Schmidt Cassegrain Visual

Available Immediately

The following list of equipment is immediately available to borrow.

  • DSLR with SCT Adapter

    Currently there are 0 requests to borrow this.

    This kit consists of a Canon XTi camera with adaper for use with a user-supplied Schmidt-Cassegrain Telescope.

  • Edmund Astroscan

    Currently there are 0 requests to borrow this.

    Table Top Newtonian Telescope

    Note: This scope has a small collimation error but it works well up to about 30x for wide field viewing.

    The Astroscan telescope is suitable for all ages. The package includes the telescope, a red circle refles sight (Rigel Quik Point) for aiming the scope, a cast-aluminum tabletop base that's padded to prevent scratches on sensitive surfaces, a user's manual, two eyepieces, and a carrying bag. The telescope is intended to be placed on a table and does not include a tripod.

    The Astroscan has a focal length of 445mm and makes a great "grab and go" scope requiring virtually no setup. It is a good telescope to use with children. Unfortunately the telescope is slightly but permanently out of collimation and is not suitable for high power viewing, but it works well with the provided low power eyepieces. A 16x eyepiece provides a three degree angle true field of view. A 25x eyepiece is also provided. The Astroscan provides good views of large star clusters and nebula, such as the Double Cluster, the Andromeda galaxy, and the Great Nebula in Orion complex, all of which can be seen from the suburbs of Seattle. It will show Jupiter and it's moons but 25x magnification is not enough to resolve Saturn's ring system.

  • ZWO ASI120MC-S Imaging Camera

    Loan ends in -31 days on April 23, 2022 (Saturday).

    The ASI120MC-S is a color USB3.0 camera. primarily intended for planetary imaging or guiding, but it can be used for deep sky imaging with some limitations.

Available Soon

The following list of equipment is currently loaned out, loan ends in the next two weeks, and no one else has requested to borrow it. This is a great time to request to borrow it!

  • APO/ZWO Advanced CCD Astrophotography Kit

    Currently there are 2 requests to borrow this.

    This astrophotography kit  is designed help capable amateur astronomers develop the skills requried to image deep sky objects. It is not suitable for beginners. Some prior observing or imaging experience with simpler equipment, such as a star tracker and DSLR camera, is strongly recommended. The borrower needs to understand how to align and use an equatorial mount. 

    The borrower must supply a laptop computer and install the necessary software to operate the camera and associated equipment.  

    The kit includes a Meade Series ED APO (apochromatic) 80mm refractor, a Celestron Advanced VX telescope mount, and a capable ZWO color CCD camera.  Beginner astrophotographers are encouraged to consider requesting and using our Star Tracker/DSLR kit or the the entry level (but capable) "APO/Ultrastar Astrophotography Kit",  prior to requesting this kit.

  • Orion 80mm ED Refractor

    Loan ends in 4 days on May 28, 2022 (Saturday).

    The Orion 80ED is a small, general purpose refractor telescope that will give sharp images of the moon and planets as well as the brighter star clusters and galaxies. ED glass improves the image contrast compared to a traditional acromat. The Twilight I Alt-Az mount is easy intuitive to use.

  • Sky-Watcher Star Adventurer Mini Tracking Mount

    Currently there are 1 requests to borrow this.

    Star Adventurer Mini is a high precision, portable star tracking platform that is useful for making wide-field images of the Milky Way with a DSLR, It includes a small equatorial mount that must be carefully polar aligned and may be confusing for beginners.. A MeFoto GlobeTrotter with a ball head is included but the user must supply their own DSLR and lens.

Available Eventually

The following list of equipment is currently loaned out to a member, and may include other members waiting to also borrow.

  • APO/Ultrastar CCD Astrophotography Kit

    Currently there are 3 requests to borrow this.

    This astrophotography kit is designed for capable amateur astronomers who wish to learn the basics of imaging with CCD cameras.  It is not suitable for beginners, and the borrower needs to understand how to align and use an equatorial mount. Some prior observing or imaging experience with simpler equipment, such as a star tracker and DSLR camera, is strongly recommended.  However, this kit does include a laptop computer with the necessary drivers and the UltraStar camera is a basic, entry level CCD. 

  • AWB OneSky 130mm Reflector

    Currently there are 2 requests to borrow this.

    Table Top Newtonian Telescope

    This telescope is suitable for all ages and is a good choice for viewing the moon, planets, and bright deep sky objects. It has a Dobsonian style mounting that is compact and intuitive to use. A red-dot reflex sight and a set of eyepieces is included.. It is designed to be placed on a small table or similar support and does not come with a tripod.

  • Orion SkyQuest XT10i

    Currently there are 3 requests to borrow this.

    10 Inch Dobsonian Computer Aided (PushTo) Telescope

    Please contact the Equipment Manager if you wish to borrow this equipment. It is a heavy and bulky telescope and it is usually loaned for extended periods.  It may require 2 people to lift it and a bigger vehicle to transport it.

    The Orion SkyQuest XT10i IntelliScope is a 10" aperture Dobsonian Reflector with a Push-To computer system for aiming the telescope. 

  • Portable DSLR Astrophotography Kit

    Loan ends in 22 days on June 15, 2022 (Wednesday).

    This is a complete portable astrophotography kit which includes the Star Watcher mount, a portable tripod, and an astronomy-modified Canon T3i with a 50mm and a 100mm lens. Note: the Starwatcher mount must be carefully polar aligned and this may be confusing for beginners.

Available by Request

Contact the Equipment Manager for more information on borrowing the following equipment.

  • Celestron Echelon 16x70 Binoculars

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

    Request queue is long. Contact the Equipment Manager for an estimated availability date..

    High Power Astronomy Binoculars

    Large-aperture astronomical binoculars are intended for wide angle viewing star clusters, nebula, and galaxies, but will also provide nice views of our Moon and Jupiter with it's four Galelian moons. These 70mm binoculars are heavy and an Orion parallelogram binocular mount and tripod is included. 16x magnification is sufficient to provide nice views of many deep sky objects, such as the Andromeda Galaxy (M31),, the Orion Nebula (M42),  and the Great Globular Cluster in Hercules (M13). It will not show Saturn's ring (about 30 power is required to reveal this detail).

  • Celestron NexStar 6 SE

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

    Request queue is long. Contact the Equipment Manager for an estimated availability date.

    Six Inch Computer Controlled (GoTo) Schmidt-Cass Telescope (SCT)

    The Celestron 6 SE is a current model computerized Schmidt-Cassegrain telescope. The 6 SE features a relatively long 1500mm focal length (f/10) and a total weight of 30 lbs including the tripod. 

  • Celestron NexStar 8 GPS

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

    Currently Unavailable - needs repair.

    8 Inch GoTo Schmidt-Cass Telescope (SCT)

    This is a heavy and bulky telescope.  It may require 2 people to lift it.

    The NexStar 8  GPS is an 8-inch aperture Schmidt-Cassegrain telescope with Celestron NexStar computer control. It is  larger adn heavier than most of the SAS loaner telescopes.  Your vehicle must accomodate three large boxes (32x20x14, 24x18x12, and 30x10x10 inches) to transport it.  The optical tube assembly is about 45 lbs.  This is not a beginner telescope.

  • Celestron NexStar Evolution 6 (#1)

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

    Special Item - Contact the Equipment Manager to borrow this premium telescope.

    Six Inch GoTo Schmidt-Cass Telescope (SCT)

    This telescope is a premium model 6 inch NexStar telescope. The loaner kit includes eyepieces, a "Red Dot"  finderscope for initial alignment, and a  good quality 1.25” star diagonal.

  • Celestron NexStar Evolution 6 (#2)

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

    Special Item-Contact the Equipment Manager to borrow this premium telescope.

    Six Inch GoTo Schmidt-Cass Telescope (SCT)

    This is a premium model Celestron 6 inch NexStar telescope. The loaner kit includes a "Red Dot" finderscope for initial alignment, eyepieces, and a  good quality 1.25” star diagonal.

  • Celestron StarHopper 8

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

    Special Item: Contact the Equipment Manager to borrow this heavy, bulky telescope.

    8 Inch Dobsonian Telescope

    NOTE: This is a heavy and bulky telescope and may not fit in smaller cars. The tube is 52" long by 10" diameter and the Base is 22" in diameter by 23" high.

    This Celestron Star Hopper Dobsonian is an 8 inch Newtonian telescope on a Dobson style mount. The telescope includes a Telrad finder that is intuitive to use and works well for pointing the telescope at the moon, planets, and brighter stars.

  • Meade 8" LX200 Schmidt Cassegrain

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

    Special Item: Contact the Equipment Manager to borrow this heavy, bulky telescope.

    8 Inch GoTo Schmidt-Cass Telescope (SCT)

    This is a large and heavy telescope. The optical tube assembly includes the fork mount and weighs 43 lbs. It is stored in a plastic tub that is 30" x 20" x 16" (L,W,H).

    This is a Meade eight Inch aperture, fork mounted,  f/10 GoTo Schmidt-Cassegrain telescope. The GoTo pointing accuracy is very good but the setup and alignment directions contained in the Quick Start guide must be carefully followed. Note that this kit does not include an optional equatorial wedge, since this is not required for visual observing.

  • Meade ETX-125 (#1)

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

    Special Item: Contact the Equipment Manager to borrow this older telescope

    5 Inch (125 mm) Maksutov-Cassegrain GoTo Telescope

    This is an older computer controlled telescope. Optical quality is very good but mechanical quality is not as good as newer telescopes. The GoTo setup procedure must be followed exactly. Beginners may need assistance.

    The Meade ETX-125EC telescope is a Maksutov-Cassegrain design that folds a relatively long focal length into a relatively short optical tube. The long focal length makes it easy to reach high magnification for observation of the moon and planets. The Meade AutoStar controller provides Go-To operation, but AutoStar is an older generation. Setup involves several steps that may be confusing for beginners,

  • Orion Resolux 10.5x70 Astronomy Binoculars

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

    Currently Unavailable

    Large-aperture astronomical binoculars are intended for wide angle viewing star clusters, nebula, and galaxies, but will also provide nice views of our Moon and Jupiter with it's four Galelian moons. These 70mm binoculars are heavy and an Orion parallelogram binocular mount and tripod is included.

  • Orion SkyQuest XT10g - Computerized GoTo Dobsonian

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

    Special Item: Contact the Equipment Manager to borrow this heavy, bulky telescope.

    10 Inch GoTo Dobsonian Telescope

    The XT10g is a 10" aperture Newtonian telescope in a motorized Go-To mount.  A red dot reflex sight finder and eyepieces are included. 

    This is a  very heavy and bulky telescope and it is usually loaned for extended periods. 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.

  • Orion StarBlast 4.5

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

     Request queue is long. Contact the Equipment Manager for an estimated availability date..

    Compact 4.5 Inch (114 mm) Newtonian Telescope

    This Orion StarBlast 4.5 reflector telescope is a good beginners telescope. Advanced amateurs will appreciate its portability and its low power, 2.2 degree field of view, which is ideal for viewing large star clusters and galaxies. It is mounted on a Twilight II Alt-Az mount that is intuitive to use.

  • Orion StarMax 127 EQ

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

    5 Inch (127 mm) Maksutov-Cassegrain Telescope with Equatorial Mount.

    Request queue is long. Contact the Equipment Manager for an estimated availability date.

    The StarMax 127 telescope has a long focal length and is ideal for observation of the moon, planets, and double stars. The equatorial mount makes it easier to track the moon and planets at high magnification, but can be confusing for beginners.

  • TeleVue Eyepiece Set

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

    Special Item-Contact the Equipment Manager to Borrow these eyepieces.

    This set includes two older wide angle Tele Vue eyepieces (16mm and 9 mm) and two newer (13mm, 8mm) wide angle eyepieces.

Telescope Types

Types of telescopes

Copyright NIAAS, North Ireland Amatuer Astronomical Society

What are those numbers?

Types of telescopes

Copyright 2008-2012 Stormthecastle.com

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: