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

The following list of equipment is immediately available to borrow.

Celestron StarHopper 8

Currently there are 0 requests to borrow this.

The Star Hopper Dobsonian telescopes are designed for beginners who seek the best possible view of the faint Deep Sky objects while on a constrained budget. These include advanced features that an experienced observer will appreciate.

 

Coronado Personal Solar Telescope

Currently there are 0 requests to borrow this.

The Coronado Personal Solar Telescope provides the ability to experience interesting details of the Sun, including sun spots and solar prominences. The PST has a bandpass of <1.0 angstrom and is quite thermally stable, requiring very little setup time. The PST will show you prominences, active regions, filaments, as well as other surface details.

Meade 8 LX200 EMC

Currently there are 0 requests to borrow this.

The Meade 8 LX200 EMC Schmidt-Cassegrain telescope is suitable for members experienced with medium to large sized computerized telescope.  This telescope is great for the visual astronomer to observe the moon, planets as well as nebulae, star clusters and galaxies.

It is loaned out fully equipped with a wide selection of eyepieces and filters as well as a JMI motofocus, an Astro chair, and astronomy books.

Orion SkyQuest XT10i

Currently there are 0 requests to borrow this.

The Orion SkyQuest XT10i IntelliScope Dobsonian Reflector features a fairly large 10" apperture mirror combined with the ease of use of a Dodsonian mount. The telescope includes altitude and azimuthal encoders and a computer controller for easy two start configuration and push-to navigation. With the Orion SkyQuest XT10i IntelliScope Computer Controller, the user can select an object to view from the controller's 14,000+ object database. A big, 9x50 finder scope is included to help aim the telescope. Three included telescope eyepieces, a 25mm, 17mm, and 9mm Sirius Plossl, provide you with views between 48x and 120x respectively. This telescope also includes a full aperture solar filter for safe solar viewing.

Available Soon

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

Celestron NexStar 114 SLT

Due back in 0 days on December 17, 2018 (Monday).

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.

Orion StarMax 127 EQ

Due back in 2 days on December 19, 2018 (Wednesday).

127mm (5") aperture combined with a very long 1540mm focal length make the StarMax 127 a Maksutov-Cassegrain telescope with multiple proficiencies. Ideal telescope for sharply detailed views of planets such as Mars, Jupiter, and Saturn, as well as the Moon and brighter deep -sky gems. High-resolution imaging and visual performance in a telescope only 14.5" long!. Includes sturdy adjustable tripod and AstroView equatorial (EQ) mount for convenient slow-motion celestial tracking. Includes a 25mm Sirius Plossl 1.25" telescope eyepiece, 6x30 finder scope, 90-degree mirror diagonal, soft case for the optical tube and accessories, EQ mount polar -alignment scope, Starry Night software, and more!

Celestron NexStar 8 GPS

Due back in 14 days on December 31, 2018 (Monday).

8-inch diffraction limited Schmidt-Cassegrain telescope

  • Fully computerized dual fork arm altazimuth mount
  • Ergonomic design--Comfortably move the telescope from location to location
  • Proven NexStar computer control technology; GPS alignment
  • 280 mm aperture, 2800 mm focal length

 

 

Available Eventually

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

Ultrastar Color Imaging Camera

Due back in 43 days on January 29, 2019 (Tuesday).

The Ultrastar camera is an advanced version of Starlight Xpress 'Superstar' guide camera and it has a similar resolution of 1392 x 1040 pixels. However, the CCD chip has 70% more area and the QE is considerably greater, at around 75% peak. These characteristics give the Ultrastar an excellent performance as both a guide camera and an imaging camera, which is especially well suited to 'Live Viewing' mode. Some years ago, Paul Shears released a simple to use program called 'Lodestar Live', which uses the SX Lodestar in 'Live Viewing' mode. This has now been upgraded to 'Starlight Live' and is capable of controlling both the Lodestar and the Ultrastar in Live view. It can also color convert and stack images from single-shots.

Celestron NexStar 102 GT Computerized Telescope

Due back in 45 days on January 31, 2019 (Thursday).

An easy-to-use computerized telescope with SkyAlign Technology. Point the telescope at three bright objects in the sky, and SkyAlign will then align your NexStar 102GT.

  • High quality 102mm (4") refractor telescope with multi-coated glass optics. 212x more light gathering power than the human eye.
  • Computerized hand control with 40,000+ objects in its database and motorized altazimuth mount
  • Special set of 5 eyepieces allowing you to view objects up to 250 times closer than the naked eye
  • StarPointer finderscope to help with alignment and accurately locating objects
  • Quick-release fork arm mount, optical tube and accessory tray for quick no-tool set up
  • Sturdy stainless steel tripod and accessory tray included
  • Includes erect image diagonal for great terrestrial observing
  • Includes TheSkyX First Light Edition Astronomy Software, which provides education about the sky and printable sky maps

Celestron NexStar Evolution 6

Due back in 47 days on February 02, 2019 (Saturday).

Celestron NexStar Evolution 6 is the first Schmidt-Cassegrain telescope with integrated WiFi. Without the hand control, slew to all the best celestial objects with a tap of your smartphone or tablet. Connect your device to NexStar Evolution’s built-in wireless network, and explore the universe with the Celestron mobile app for iOS and Android.

Use the planetarium interface to view the night sky in real time or display a list of celestial objects currently visible based on your time and location. Our proprietary SkyAlign alignment procedure is built right into the Celestron mobile app, so you’re ready to observe within minutes.

NexStar Evolution includes its own built-in battery. With this ultra-long life lithium-iron phosphate battery, you’ll be able to enjoy stargazing marathons up to 10 hours on a single charge.

Setting up your NexStar Evolution is quick and painless with large, ergonomic handles. Manual clutches in both altitude and azimuth offer greater flexibility to manually point the telescope when powered off.

The 6-inch NexStar Evolution is an excellent way to get started in astroimaging. NexStar Evolution’s tracking accuracy is so impressive, you can capture images of deep-sky objects like the Orion Nebula by simply attaching your DSLR camera.

The Schmidt-Cassegrain optical system offers bright, sharp views with StarBright XLT optical coatings—a great choice for visual observers and budding astroimagers alike.

NexStar Evolution is equipped with 4 auxiliary ports--2 on top of the fork and 2 on the bottom. A classic NexStar+ hand control is included, but is not necessary when using NexStar Evolution with the mobile app. The telescope also includes a StarPointer finderscope, two 1.25” Plossl eyepieces, a 1.25” star diagonal, and an AC adapter.

Echelon 16x70 Binoculars

Due back in 49 days on February 04, 2019 (Monday).

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.

 

ZWO ASI120MC-S Imaging Camera

Due back in 49 days on February 04, 2019 (Monday).

ASI120S is a super speed and sensitive USB3.0 camera. Up to 60FPS under 1280X960 full resolution! With a peak QE of 75%, beyond ICX618 and with no FPN(Fixed pattern Noise)! Long time exposure supported up to 1000s! Full compatible with USB 2.0 USB Host!

Sky-Watcher Star Adventurer Mini Tracking Mount

Due back in 63 days on February 18, 2019 (Monday).

Star Adventurer Mini is a high precision, portable and stable tracking platform for sidereal, solar and lunar tracking with automatic DSLR shutter release control.

Whether you’re looking for a tracking platform to capture wide-field images of the Milky Way, or seeking a compact travel mount, Star Adventurer Mini is a necessity for astrophotographers of every skill level. This high precision, portable celestial tracking platform can transform almost any tripod into an equatorial mount, assisting photographers with long exposures of the night sky. Star Adventurer Mini breaks from the mold of traditional equatorial mounts with an abundance of add on accessories to complement wide-field astrophotography, nightscape images or time-lapse photography.

A Star Adventurer Latitude Base in provided. The Star Adventurer Latitude (EQ) Base provides a smooth and reliable way to polar align your mount. With internal gearing the Latitude Base makes aligning to the north celestial pole easy and repeatable.  A MeFoto GlobeTrotter with a ball head is also provided.

Orion Resolux 10.5x70 Astronomy Binoculars

Currently there are 1 requests to borrow this.

Resolux binoculars are our new favorite astro binoculars (and equally superb for long-distance daytime viewing), combining high-resolution, flat-field optics with rugged mechanical construction and the strict JTII spec for collimation. They are fully waterproof, and nitrogen purged to prevent internal lens fogging. The BAK-4 prisms and advanced multi-coatings on all optical surfaces really drink in the light. The eyepieces focus individually, and with 18mm or more of eye relief on each model, even eyeglass wearers will see the full field of view. The Resolux's all-metal housing is armored with thick rubber to ensure a secure, comfortable grip. Each binocular comes with tethered lens caps, heavy-duty tripod adapter, and neck strap.

These rugged 10.5-power Orion Resolux astronomical binoculars provide high-resolution views with a nice flat-field. Fully waterproof and nitrogen purged construction prevents lens fogging in damp conditions. High-quality BAK-4 prisms and advanced multi-coatings on all optical surfaces provide maximum light throughput for bright views rich in contrast. Orion's 10.5x70 Resolux binoculars are still hand holdable for short viewing sessions, and have a nice 5.0-degree field of view.

Orion StarBlast 4.5

Currently there are 1 requests to borrow this.

The Orion StarBlast 4.5 EQ reflector telescope is suitable for beginner and intermediate astronomers. It comes with a sturdy EQ-1 equatorial tracking mount and adjustable-height tripod. Included are two eyepieces from the Orion Expanse series - a 15mm and 6mm - which have a large 66 degree apparent field of view. The included 15mm Expanse telescope eyepiece provides 30x power magnification, while the 6mm Expanse eyepiece bumps up the power all the way to 75x magnification.  An included Orion EZ Finder II reflex sight makes it easy to effectively aim the StarBlast 4.5 Equatorial Reflector Telescope anywhere in the night sky. The EZ Finder II projects a small red-dot onto a viewing window so all you have to do is move the telescope until the red-dot is aimed at the area of sky you wish to view through the telescope.

Meade ETX-125EC

Currently there are 1 requests to borrow this.

The ETX-90 Maksutov-Cassegrain offers good optical quality in an easily transported smaller apperture telescope.  The Meade AutoStar computer handbox with over 30,000 object library and a solid mount and tripod make this an excellent choice for new observers looking for a portable scope that can be set up quickly.

 

Explore Scientific AR102mm Refractor

Currently there are 2 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.

Portable Astrophotography Kit

Currently there are 3 requests to borrow this.

This is a complete portable astrophotography kit which is suitable for wide-field astro-imaging.  The equipment includes a Sky-Watcher Star Adventurer equatorial mount, Berlebach mini tripod, astronomy-modified Canon T3i with a 50mm and a 100mm lens, assorted cables, batteries, and cases (one for the mount and camera and one for the tripod).  It comes with a manual to familiarize the user with the assembly, use, and care of the Seattle Astronomical Society’s portable astrophotography equipment.

Advanced Astrophotography Kit - Meade 80mm Refractor

Currently there are 4 requests to borrow this.

This advanced astrophotography kit includes a Meade Series 6000 APO ED APO 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.

The Meade Series 6000 80mm APO triplet refractor is built with the observer and imager in mind.  With the three element optical design using the highest grade extra-low dispersion optical glass, false color is virtually eliminated, yielding astonishing color correction, contrast, and sharpness.

Currently Unavailable

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

Edmund Astroscan

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

The Edmund Scientific Astroscan 4 1/8" Telescope comes in a basic package that includes the telescope, an open sight target finger, a cast-aluminum tabletop base that's padded to prevent scratches on sensitive surfaces, a user's manual, an eyepiece and a carrying bag. The Astroscan has a three degree angle of view at 16X and makes a great beginner's scope requiring virtually no setup. It is very light-weight and perfect for small children.

Orion SkyQuest XT10g - Computerized GoTo Dobsonian

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

The SkyQuest XT10g features GoTo pointing convenience. It features a 254mm (10") aperture, 1200mm focal-length parabolic mirror (f/4.7) made from low-thermal-expansion optical glass. Enhanced reflectivity (94%) aluminum mirror coatings yield bright, high-definition images. The 10" primary mirror is center-marked to make precise alignment of the optics (collimation) easier to achieve. The reflector telescope's open mirror cell design facilitates efficient cooling of the mirror to ambient temperature.

The XT10g telescope optical tube drops into the Dobsonian base on a dovetail trunnion and locks in place with a single hand knob. A simple two-star alignment is all it takes to orient the telescope to the sky for GoTo operation. Then let the fun begin! When you're ready to call it a night, just loosen the knob and lift the tube off the base for easy transport or storage. Handles on the Dobsonian base's front and side panels make it easy to lift and carry, whether you're going from car to field, or from house to backyard.

The Orion SkyQuest XT10g GoTo Dobsonian also includes an EZ Finder II reflex sight, eyepiece rack for one 2" and three 1.25" eyepieces, hand controller bracket, and a quick collimation cap.

Tele Vue Eyepiece Set

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

All Tele Vue eyepieces have proprietary tuned full multi-coatings, blackened lens edges, high index glasses, fold-down eyeguards, rubber grip rings, cover for the eyeguard, an undercut in the barrel for extra locking security and filter threads.

Celestron NexStar 6 SE

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

Portability and serious performance come together in the NexStar 6 SE. Celestron's first new Schmidt-Cassegrain optical system in over a decade is now available in a high performance Altazimuth computerized telescope. With a total weight of 30 lbs including the tripod, the ultra portable 6 SE features a precision optical system with 1500mm focal length (f/10) and offers 44% more light gathering than a 5" telescope.

Telescope Types

Types of telescopes

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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: