Brands - JMI

JMI

Menu

Dobsonian Telescopes


Dobsonian Telescopes
If your passion is to visually observe deep space objects, large Dobsonian telescopes are the ultimate tool for the job. Dobsonian telescopes are popular because they offer the most available aperture for the dollar. While they may not look like a telescope to the first time buyer, virtually all amateur telescopes over 14 inches in aperture are Dobsonians because other optical designs become impractical in such large apertures. Dobsonian telescopes combine Newtonian reflector optics with a simple, cost effective and easy to use altazimuth mount. These telescopes are named for their designer, John Dobson, who sought to build a low cost large aperture telescope. The larger models disassemble into smaller and lighter components, making it possible to transport a large instrument to a dark site. No other design has had a greater impact on amateur astronomy in the past half century.

Dobsonian Telescopes

Celestron Starsense Explorer 114mm Tabletop Dobsonian
More Details
$349.95

Free Shipping

Celestron Starsense Explorer 12-inch Dobsonian
More Details
$1499.00
Celestron Starsense Explorer 130mm Tabletop Dobsonian
More Details
$449.95

Free Shipping

Celestron Starsense Explorer 150mm Tabletop Dobsonian
More Details
$559.95

Free Shipping

Sky-Watcher Classic 150P Dobsonian
More Details
$460.00
Celestron Starsense Explorer 8-inch Dobsonian
More Details
$799.95
Sky-Watcher Classic 200P Dobsonian
More Details
$655.00
Sky-Watcher Flextube 200P Dobsonian
More Details
$755.00

Free Shipping

Sky-Watcher Flextube 200P SynScan Dobsonian
More Details
$1450.00

Free Shipping

Celestron Starsense Explorer 10-inch Dobsonian
More Details
$1099.95
Sky-Watcher Classic 250P Dobsonian
More Details
$910.00
Sky-Watcher Flextube 250P Dobsonian
More Details
$1020.00

Free Shipping

Sky-Watcher Flextube 250P SynScan Dobsonian
More Details
$1715.00

Free Shipping

Sky-Watcher Flextube 300P Dobsonian
More Details
$1715.00

Free Shipping

Sky-Watcher Flextube 300P SynScan Dobsonian
More Details
$2560.00

Free Shipping

Sky-Watcher Flextube 350P SynScan Dobsonian
More Details
$3615.00

Free Shipping

Sky-Watcher Flextube 400P SynScan Dobsonian
More Details
$4680.00

Free Shipping

Dobsonian Telescopes

Dobsonian telescopes are also commonly referred to as light buckets. When it come to observing deep space objects, light gathering aperture is the single most important factor. Dobsonians combine medium to large aperture Newtonian Reflector optics with a simple lazy Susan style altazimuth mount that sits directly on the ground. This keeps the cost low without having to compromise on the size or quality of the optics. Dobsonian telescopes are the undisputed champions of deep space observing; do not be surprised to see a 25 or even 30 inch Dobsonian at your first major star party.

Types of Dobsonian Telescope: It's All About the Optical Tube

As stated above, the largest amateur telescopes available are Dobsonians. Large telescope are just that, large! Three types of Dobsonian telescope are commonly available for sale. The choice between them generally comes down to what is practical based upon the aperture of the telescope. These types include the following:

  • Solid Tube Dobsonian Telescopes: Dobsonians with solid tubes are popular in telescopes with smaller apertures, at least as far as Dobsonians go. The optical tube assembly is a one piece affair. The most common sizes offer six, eight, and 10-inches of aperture. Twelve inch solid tube Dobsonians are available, but most people find the optical tube assembly to be too heavy and unwieldy to be practical. The most common examples for Solid tube Dobsonians are the Sky-Watcher Classic and Orion Skyquest models.

  • Collapsible Tube Dobsonian Telescopes: Collapsible Dobsonians feature a one-piece optical tube assembly that is capable of collapsing upon itself to reduce the overall length. The lower part of the tube with the primary mirror and upper part with the secondary mirror and focuser are permanently connected with metal poles. With the flick of some locking levers, the entire assembly can collapse upon itself. Collapsible Dobsonians make the most sense in 12 and 14-inch apertures, where the collapsed length of the optical tube will fit across the back seat of a car. Smaller collapsibles have little benefit, other than a reduction in storage space. Larger collapsibles are too heavy and unwieldy to be practical. Note that the collapsible design requires the base assembly to be taller than the other types, which may be a factor to consider for both transportation and storage. Sky-Watcher Collapsible Dobsonians are an example of this type.

  • Truss Tube Dobsonian Telescopes: Truss tube telescopes make a great deal of sense for apertures of twelve inches or more. A lower mirror box housing the primary mirror is connected to the upper cage assembly with the secondary mirror and focuser using removable truss poles. Unlike the other two types above, this distributes both the weight and length of the fully assembled optical tube across a number of smaller and lighter components. This is what makes very large aperture telescopes practical for transportation to dark sites. Note that the base assembly of a truss tube Dobsonian is shorter, but also wider than the other types. These telescopes must be assembled in the field before they can be used. The Meade LightBridge, Orion SkyQuest XX12 and Sky-Wathcher StarGate are examples of large aperture truss tube Dobsonians.

What to Expect in a Dobsonian Telescope

Founded by amateur astronomers passionate about their hobby, we at Skies Unlimited have been working with hobbyists since 2004 and know what it takes and what our customers expect. That’s why we offer excellent options in Dobsonian telescopes, along with professional advice you can use to buy the best Dobsonian telescope for your needs and experiences.

Throughout the years, we've come to work with numerous quality Dobsonian telescope manufacturers, including Meade, Orion and Sky-Watcher. We offer a wide variety of options from each of these companies so you can find the best fit for your needs and experience.

Learn More - Telescope Optical Designs

Newtonian Reflector Telescope

Newtonian Reflector Telescopes

Newtonian reflector telescopes are an optical design that use a mirror to focus light into a smaller area. Most of the larger telescopes in use today utilize mirrors for economic reasons. It is less expensive to produce a mirror than a lens, and that advantage grows with the size of the telescope. The main advantage of a Newtonian Reflector is cost per unit aperture. The disadvantage is the images they produce are upside down, meaning that they are not suitable for terrestrial observing.

Dobsonian Telescope

Dobsonian Telescopes

A Dobsonian telescope is a Newtonian reflector mounted on a simple yet stable alt-azimuth (lazy Susan style) mount. These telescopes are named for their designer, John Dobson, who sought to build a low cost large aperture telescope. No other design has had a greater impact on amateur astronomy in the past half century. Dobsonian telescopes are popular because they offer the most available aperture for the dollar. Dobsonian telescopes may appear unconventional to the first time buyer, but the fact is that they dominate the market for amateur telescopes over eleven inches in aperture. Wikipedia has a fine article on the history and origins of the Dobsonian Telescope.

Refractor Telescopes

Refractors

Refractors or refracting telescopes are a design that use only lenses to focus the light; every other type of telescope relies on one or more mirrors to do that job. The long, slender optical tube of a refractor is the image that most people associate with a telescope. Refractor telescopes have the advantage of having an unobstructed light path, which produces higher visual contrast than other optical designs. Stars appear as pinpoints against an inky black background when viewed in a refractor. Refractors have the disadvantage of being the most costly per unit of aperture, which is why refractors tend to be smaller than all other designs.

Schmidt-Cassegrain Telescope

Schmidt-Cassegrain Telescopes

Schmidt-Cassegrain telescopes use both mirrors and a lens (corrector plate) to focus light into a smaller area. Schmidt-Cassegrains are popular due to their compact size relative to their aperture. These are the Jack of all trades in the telescope business. They are moderately well adapted to a wide variety of applications, including lunar, planetary, deep space, and even terrestrial observing. Variations on the Schmidt-Cassegrain design include Celestron's EdgeHD and Meade's Advanced Coma Free (ACF) optical systems. The primary advantage of a Schmidt-Cassegrain telescope is that it tends to offer the greatest degree of portability per unit of aperture. The disadvantage is they are more costly than Newtonian Reflectors.

Maksutov-Cassegrain Telescope

Maksutov Cassegrain Telescopes

Maksutov-Cassegrain telescopes are similar to Schmidt-Cassegrains, using both mirrors and a lens to focus light into a smaller area. Maksutov-Cassegrains replace the flat corrector plate of the Schmidt-Cassegrain with a convex meniscus lens. The secondary mirror is actually a silvered spot on the inside of the meniscus lens. This in itself leads to one major advantage: Maksutovs do not require periodic collimation of the optics as do Schmidt-Cassegrains and Newtonians. Maksutov-Cassegrains offer superior contrast to a Schmidt-Cassegrain, but they are also more expensive per unit of aperture.

Solar Telescope

Solar Telescopes

Solar telescopes offer a safe way to observe and study our nearest star: the sun. This is a highly specialized field and the number of suppliers is considerably smaller than that for general purpose telescopes. We offer solar telescopes from Lunt Solar Systems, Coronado, and DayStar Filters, that are filtered for the Hydrogen-Alpha and Calcium-K spectral lines. Often it is more cost effective to purchase a dedicated solar telescope than it is to add a solar filter to an existing one.

Feeling Overwhelmed?

Don't worry, this happens to a lot of people. If this is your first time shopping for a telescope, please take a few minutes to read our article Advice for First Time Telescope Buyers before proceeding any further. We think that you will be glad that you did.