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.
Have questions about which Dobsonian telescope in our selection you should choose? We at Skies Unlimited are ready to help you with our personal experiences in amateur astronomy. We’ll pinpoint your needs, expectations and experience and find the best Dobsonian telescope and set of accessories for your needs. Our real observers can give you the honest advice you need to get off the ground.
Regardless of whether you’re visiting our physical Skies Unlimited Retail Store location just outside of Pottstown, PA or browsing through our collection online, feel free to call us. Any members of our staff are ready and able to answer your questions and provide you with information about the product’s dimension, weight and capabilities.