Dobsonian is a name for one type of telescope base. Dobsonian telescope bases move in two directions, up and down and left and right; astronomers refer to this as altitude and azimuth or alt-az. Dobsonian bases are designed to be affordable and easy to use.
The Dobsonian base is usually made from coated plywood and the part of the base that makes contact with the ground is much like a lazy susan and it moves around in a circle, and the telescope sits on top and can swing up or down.
The lazy susan is made with roller bearings that allow the scope to move smoothly from left to right, what astronomers call azimuth.
Dobsonian bases were designed by amature astronomer John Dobson. He designed the telescope to be easy to use and easy to construct.
John compares the telescope design to the cannon. He modeled his base after those that held cannons. He said he did not invent anything! We already had it!
John Dobson’s simple view of astronomy has played such a big role in the hobby, making large telescopes affordable for backyard astronomy.
How Do Dobsonians Work?
Dobsonian bases work by holding the telescope by two clutches on the side of the optical tube and allows the telescope to swivel from side to side.
Dobsonian bases are made from 2 or 3 uprights and a sandwich of bases with roller bearings in between.
Dobsonian mounted telescopes are very intuitive for beginners and they are also portable. This makes them a great choice for a new astronomer.
Dobsonian mounts are generally all one piece and they can be placed directly on the ground and then the telescope is placed on the mount with no screws or brackets.
The part of the telescope that slides into the base are called clutches and they can be tightened to keep the telescope steady or loosened to move the scope.
Dobsonian mounted telescopes can be manual, hand controlled or completely computerized. Manual telescopes will be the most affordable and you can add the electronic components later in most cases.
You can still find free instructions for making a Dobsonian telescope on the Sidewalk Astronomy website.
When using a large Dobsonian mounted telescope it can be much more comfortable with an observing chair.
Are Dobsonian Telescopes Any Good?
Dobsonian mounted telescopes are excellent telescopes, they are generally better for visual observing than astrophotography. These Newtonian reflectors are the best way to get the most aperture for your money.
Dobsonian mounted telescopes are often recommended for beginners because they are easier to use and more affordable than equatorial mounted telescopes.
Dobsonian telescopes allow you to afford a larger aperture. This means your telescope will be able to collect more light, making objects appear brighter.
You can see some examples in our articles about 10” Dobsonians, 12” Dobsonians and 16” Dobsonians. These articles include pictures so you can see the difference you can expect as you increase the aperture of your telescope.
I have owned two Dobsonian telescopes and they have been excellent instruments for me. I travel often with the telescopes and I do a lot of star parties in my small town. These scopes are great.
Beginners can get a tabletop Dobsonian that is high quality for a very affordable price on Amazon.
What Are Dobsonian Telescopes Good For?
Dobsonian telescopes are good for visual observing of planets, galaxies and nebulae. They are great for beginners because of their lower price and simple design. However, they are not the preferred type of telescope for astrophotography, but short exposure photography is possible.
Dobsonian telescopes are great because of the large aperture. This makes dim distant objects brighter and easier to see.
This makes them great telescopes for observing nebulae and galaxies.
They can be computer controlled or “go-to” telescopes or manually directed telescopes.
Dobsonian telescopes are also good for outreach, they are solid telescopes that cannot be damaged easily.
I travel with my scope every time I observe and the frequent moving has not damaged the scope at all.
Can a Dobsonian Telescope Be Motorized?
Dobsonian mounted telescopes can be fully manual, fully computerized or hand controlled.
Motorized telescopes are called go-to telescopes and they have two motors that move the telescope to point to a selected object.
Go-to telescopes are much more expensive than manual telescopes, but they make it much easier to find things while observing.
If you already own a Dobsonian telescope you can add digital setting circles to make your telescope a push-to. This makes it easier to find things, but does not move the telescope.
