If you have found yourself browsing for telescopes and are suddenly confused by what appears to be some kind of secret code in the names, do not worry, it has happened to all of us. You were just looking for a basic telescope to start with when you suddenly run into strange looking things such as 70AZ, 100EQ, 102SLT, and others. Suddenly, you feel as though you are missing a crucial piece of information.
These are shorthand ways of quickly conveying information about the telescope in question to a knowledgable audience. It is much simpler than it looks.
For instance, the AZ in these names does not stand for Arizona but rather altazimuth. Altazimuth is the type and style of the mount which comes included with the telescope in question. If you see a telescope name like Celestron PowerSeeker 80AZ, that means you are getting a telescope with an altazimuth mount.
Altazi-What?
Altazimuth, say it three times fast. This is a word that casual people rarely run into in their day to day lives so its understandable to be in the dark as to its meaning. An altazimuth mount is simply one that is able to move both vertically and horizontally. It gives you the ability to manually move both up and down.
The word comes from a combination of the words azimuth and altitude.
Azimuth is the scientific term used for the vertical axis when talking about telescopes and other similar devices.
Altitude is the term used for the horizontal axis.
Put those two things together and you get altazimuth.
Difference Between a Mount and a Base
AZ and altazimuth refer to the telescope’s mount which is very different from a telescope’s base. This can also be confusing to some people. The mount is the attached device that allows you to move the optical tube assembly (OTA) in order to reposition it during viewing. The base is the thing on which the telescope itself and the mounting array both sit.
For example, most telescopes whether they have an altazimuth mount or not, will sit on a tripod base.
There are other kinds of bases too such as a Dobsonian base or flat bottomed tabletop base. In any of these cases, the base is a completely separate entity from the mount. The mount and base have to work together to keep the telescope upright and moving but the terms altazimuth or AZ has nothing to do with the kind of tripod that the OTA will sit on.
How Does An AZ Mount Handle?
In short, altazimuth mounts handle very well. Their ability to move both up and down, side to side, with complete ease gives you total freedom to move the telescope where you wish in relation to the objects you want to view.
They are not complicated to use, they require no prior knowledge and no calibrating or aligning to use. This makes AZ mounts the easiest and most user friendly mounts to use by far. It is going to feel the most natural to anyone who is not familiar with astronomy or photography.
This freedom of movement can lead to some unintended consequences such as annoying micro-movements which can easily move your aperture out of alignment ruining what was a great view and requiring you to readjust the mount.
It also has the unintended consequence of being great for terrestrial viewing. Some people use their refractor telescopes to view landscapes right here on Earth and the altazimuth mount is perfect for that dual purpose use as well.
Final Thoughts
Astronomy is a fascinating hobby fraught with tons of intimidating terms and phrases that can seem confusing at first. It will take some time to recognize and understand them all but once they start coming together, the puzzle that is backyard astronomy becomes clearer.
Altazimuth is a mouthful of a term for a simple concept. It is a telescope base that is able to move upwards and downwards, left and right, all by manual input. Altazimuth mounts can move on the azimuth and the altitude freely. This gives the user complete freedom and control to steer their telescope any which way while viewing the night sky.
