Find out how to observe the sky using one of the simplest beginner telescope mounts to get started. Stable but easy to handle, the Dobsonian mount offers one of the easiest and most enjoyable ways to use a telescope.
In the 1960s, John Dobson, a California-based amateur telescope maker, wanted to mount his Newtonian telescopes in a simple, easy and inexpensive way. At the time, almost all Newtonian telescopes were mounted on a large German equatorial mount, a type of mount that is neither cheap nor easy to use for a beginner and is far from transportable. John Dobson took up an old idea : an altazimuth mount (vertical axis) built with modern materials that one could easily obtain. Innovations included the use of Teflon and Formica in load-bearing surfaces, materials that allow fluid movement. Telescopes with this kind of plastic base can only be moved if they are pushed and they do not deviate once they are pointed.
Dobsonian telescopes gained popularity in the 1960s and 1970s, but by the 1980s, more and more were being made. Today, the Newtonian telescopes mounted on a Dobsonian mount is one of the most popular types of telescopes. There are different sizes : from 4 to 30 inches.
Set up a Dobsonian mount step-by-step
- Choose a location
Although Dobsonian mounts take up less floor space, they should be placed on a sturdier, dryer, and more flat surface than a tripod because the wooden support is flat and has small feet at the corners.
- Make sure to balance it
Make sure the Dobsonian telescope is well balanced with its various accessories. A heavy eyepiece or digital camera may need to be counterbalanced at the other end of the tube.
- Align the mirrors (collimation)
Moving a Dobsonian telescope can disrupt mirror alignment, so check the collimation of your Dobsonian telescope before observing the sky. It’s better to do it in the light. Also check the finderscope when you are in the field.
- Adjust the tension
Many Dobsonian telescopes have a clamping screw to adjust the altitude or azimuth, which affects the amount of force needed to push or pull the telescope to point it. Adjust the clamping screw to follow the celestial objects with minimal effort.
- Pay attention to security
You will probably need a stepladder to access the eyepiece of a large Dobsonian telescope when it is pointed high in the sky, so pay attention to your safety.
- Effective pointing
For ease of pointing, Dobsonian telescopes are the least effective when they are directed towards celestial objects near the zenith. This area, directly above the observer, is sometimes called a “Dobson hole”.