The different types of telescope mounts explained
Last Updated: August 16, 2022
The telescope mount is what supports the telescope and allows you to aim it at different objects in the sky. Many seasoned astronomers may agree with me when I say they are in fact a crucial part of the entire telescope set-up. When you are first starting out in the hobby, it may be a little confusing to understand the different types of mounts available on the market. I know this was certainly the case for me!
Three of the most popular types of telescope mounts are called Dobsonian, altazimuth, and equatorial. In addition, there are two more technologically advanced mounts: the startrackers and the GoTo mounts.
In this article, I will run through the different types of telescope mounts, and their key features. After reading this, I hope you will better understand which one is best suited for your needs.
The altazimuth mount (Alt-Az)
The Alt-Az mount is the simplest type of mount available. It consists of two axes – one horizontal (azimuth) and one vertical (altitude). This design makes it very easy to use, as you can simply move the telescope up/down and left/right to point it at the object you want to look at.
Some of them are equipped with a slow-motion knob that helps you fine-tune the movement of the telescope. That’s a convenient feature that allows you to smoothly track the observed object in the centre of your eyepiece.
Alt-Az mounts are usually made of lighter materials such as aluminium, which makes them quite portable. This is a great feature if you plan on taking your telescope to different locations or on camping trips. However, the lighter weight also means that they are not as sturdy as some of the other types of mounts.
This type of mount is mostly paired with entry-level refractor telescopes and best fits the occasional stargazers who enjoy short observing sessions, like full moons or planetary opposition. Unfortunately, if you are into photography, there are much better mounts for that, which we will see later.
This short refracting telescope is mounted on a basic altazimuth mount.
The Dobsonian mount (Dob)
Dobsonian mounts were designed to carry large reflecting telescopes. It is the simplest type of mount and is a very popular choice among amateur astronomers. It is essentially an altazimuth mount, which means it moves up/down and left/right, but not around in a circle.
Dobsonian mounts are usually very large and bulky because they need to be able to support a heavy telescope with a large aperture. They are usually made of wood or plywood, which makes them quite cheap to produce. However, they are less portable than altazimuth mounts because of their large size and weight, they also use up more space for storage.
To point your OTA towards your chosen target in the sky, you will first have to manually orient the telescope to the right or left by gently pushing the azimuth turntable. Then you will need to adjust the altitude axis by turning the control knob on the side of the rocker box, which allows you to move the optical tube up or down. Once you have your desired target in the centre of the eyepiece, you can tighten the control knob to hold the tube in place.
Dobsonian mounts are indeed very simple in design and easy to manufacture, which is part of the reason why they are so affordable. They are quite robust too which is particularly important when using large aperture telescopes.
When placing your Dobsonian mount on your observing spot, make sure that the base is properly levelled on the ground. Some astronomers also place their mount on a vibration pad which significantly reduces vibrations around the telescope and makes for a better viewing experience
Dobsonian mounts are particularly well-suited for regular stargazers who have a keen interest in doing long observing sessions and making the most out of their local night sky.
Dobsonian mount can carry very heavy telescope tubes.
The equatorial mount (EQ)
The equatorial mount is the type of mount you will see on most high-end telescopes. It is a bit more complex than the altazimuth and Dobsonian mounts, but it has some very interesting features that make it worth the investment for serious astronomers.
As its name suggests, an equatorial mount has one axis that is aligned with the Earth’s rotation axis. This is the right ascension axis and it needs to be pointing towards the north or south celestial pole, depending on your location. The other axis, called the declination axis, is perpendicular to the polar axis and moves in an east-west direction.
The main benefit of using an equatorial mount comes from the fact that it allows you to smoothly track astronomical objects as they move across the night sky. Equatorial mounts are mostly made of metal, which makes them quite sturdy and stable. This is particularly important because you want to avoid any vibrations when using high-magnification eyepieces.
To use an equatorial mount, you will need to do a bit of set-up before you can start observing:
- Place the tripod on a flat surface and level the mount using a spirit level.
- Point the right ascension axis towards the north or south celestial pole, depending on your location.
- Use the counterweights to balance the telescope’s tube to ensure movements are fluid.
You can start manually tracking any objects or, alternatively, there is a small motor unit available on the market that you can use on EQ mounts. These will turn your manual tracking mount into a “GoTo” mount of sorts. It won’t be as precise tho.
German equatorial mount (GEM)
The German equatorial mount, also known as a GEM, is very similar to a regular equatorial mount. The main difference is that the polar axis is positioned at an angle, rather than being perpendicular to the ground like on an EQ mount.
Fork mount (FM)
Fork mounts are the type of mount you will see on most commercial telescopes, such as the ones sold by Celestron and Meade. They consist of two “forks” that hold the telescope tube in place.
Fork mounts are very sturdy and can support a fair amount of weight. That’s why you’ll see these types of mounts on Schmidt-Cassegrain and Maksutov telescopes.
The computerized GoTo mount
The computerized goto mount is the most expensive and advanced type of mount available on the market today. It is a motorized mount that is controlled by a computer system. This system tells the mount where to point the telescope at any given time.
The goto mount is very popular among astrophotographers because it makes it very easy to find and track objects in the night sky. All you have to do is:
- Input the date, time, and geolocation into the handset.
- Perform a three-star alignment so that your telescope is aligned with the rotation of the sky.
- Input the desired object into the computer system and the mount will do the rest.
Goto mounts are available in both equatorial and altazimuth designs. Since they are so precise in keeping celestial objects in the centre of the eyepiece, these self-guided mounts are perfect for taking long-exposure images. This allows astrophotographers to gather as much light as possible with little to no perturbation, resulting in stunning images of deep-sky objects.
But because of their many moving parts and advanced design, computerized goto mounts require more maintenance than other types of mounts. Should any issue arise in the long term, it might not be as easy to fix as with a Dobsonian or an equatorial mount. You may need to find a specialist to take a look at it. They might be rare and/or costly.
It comes as no surprise that GoTo mounts are the most expensive type of mounts, with some models costing over $10,000. Overall, they are great for anyone who wants to get into astrophotography or simply wants an easier way to find and observe objects in the night sky.
The Star trackers
Star trackers are basically a mini version of the computerized goto mount. It is a motorized mount that is used to keep a camera pointed at a particular object in the night sky for long-exposure astrophotography. Just like the larger goto mounts, star trackers use a computer system to control the motors.
The main advantage of these mounts is their portability. They are small enough to fit in a backpack, making them great for travelling astrophotographers who want to take some pictures of the night sky on the go. Another advantage of star trackers is that they are relatively easy to set up and use. They compensate for the Earth’s rotation, allowing you to take long-exposure photos without star trails.
However, there are some disadvantages to using a star tracker. The main one is that they can only be used for astrophotography and not really for visual observation. They also have a limit to how heavy of a load they can carry. This means that they can not be used with heavy OTAs, mostly just small apochromatic refractors with a DSLR camera attached to them.
You can find very good Star trackers for around $500, which makes them a more affordable option for beginner astrophotographers. But because they are mostly used for one specific purpose, they might not be the best investment for everyone.
Overall, there is no one “best” type of telescope mount. It really depends on your specific needs and wants. If you want to get into astrophotography, then a computerized goto mount or a star tracker might be a good option for you. But if you just want to do some casual observing of the night sky, then a Dobsonian or an equatorial mount might be a better choice.
I started off my stargazing journey with a Dobsonian telescope and I definitely have a soft spot for that type of telescope. I became familiar with the night sky due to the user-friendly nature of this telescope and I still use it today.
But whatever type of mount you choose, make sure that it is something that you are comfortable using. After all, the best telescope in the world won’t do you any good if you can’t use it properly. A good mount is an important investment and it can make a big difference in your stargazing experience.
Thanks for reading, and clear skies!
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