One of the most important things, if not the most important, for you as an amateur astronomer is your telescope mount.
The mount is the foundation of your entire setup. It determines how well you can observe or photograph celestial objects in the night sky.
Your mount selection determines if you can track objects in the sky as you had hoped. Choose wrong, and you could find yourself with a fancy high-tech go-to mount that’s too much for you to deal with, especially in the field.
But what is a good mount for you? Of the various types of telescope mounts available, which one best meets your needs, today and for the future? I will answer these questions in this article and help you confidently select your telescope mount.
The types of telescope mounts are easy to list.
There are two main categories: Altazimuth and Equatorial. Within each of these categories, there are two types of telescope mounts.
There are either regular Alt-Az Mounts or Dobsonian Mounts for the Altazimuth category.
There are either GEM (German Equatorial Mounts) or Fork Mounts for the Equatorial category.
The more complicated part is knowing which one to use, for which purpose, and why.
This article aims to help you confidently choose a particular type of telescope mount based on your specific situation.
In this article, you get
A questionnaire to guide you into one of the four telescope mount types
A detailed description of each of the four mounts
A look at the advantages and disadvantages of each type of mount
By the end of this article, you’ll understand the different types of mounts and why you’re choosing one type over the others.
Let’s dive right in.
TYPES OF TELESCOPE MOUNTS: THE BASICS
All mounts support and stabilize your telescope, allowing you to point your telescope at specific objects in the night sky.
As mentioned above, the four main types of telescope mounts are:
- Alt-Azimuth Mounts (Alt-Az)
- Dobsonian Mounts (Dob)
- German Equatorial Mounts (GEM)
- Fork Mounts (Fork)
HOW TO CHOOSE YOUR FIRST TELESCOPE MOUNT
I want to ask you a few questions to help guide you in choosing one of the four types of mounts.
By having one of the mounts in your mind as your preference, you will find it easier to compare and contrast your selected mount with the others.
When I dive deeper into each type of mount, including their advantages and disadvantages, you can reconfirm your selection or, if needed, come back to this questionnaire and make a different choice.
QUESTION 1 OF 3: VISUAL OR PHOTOGRAPHY?
What type of astronomy are you planning to do with your telescope?
Are you planning for mainly visual observing of the night sky and perhaps some terrestrial observing during the daytime?
Or, are you instead planning on using your telescope to take photographs of celestial objects?
If you’re planning for astrophotography, are you looking to take photos of bright planets or faint deep-sky objects, like nebulae and distance galaxies?
The answer to these questions will already steer you toward one of the two categories.
For visual observation, use an Alt-Az mount (Altitude-Azimuth mount)
For astrophotography, use an EQ mount (Equatorial mount)
However, it’s more complicated.
You could, for example, use an Equatorial mount for visual observation just as well.
For this article, and to keep things simple, I’ll provide you with my recommendation and support it with rationale. If your rationale differs from mine, choose differently from my recommendation.
Suppose you’re a newcomer to astronomy or don’t have any particular interest in taking long-exposure photos of very faint and distant deep-sky objects. In that case, I recommend you choose the Altazimuth category.
Alt-azimuth mounts are far more straightforward than Equatorial mounts, and based on your answer; there is no need to get an Equatorial mount since it will only add to the complexity. Alt-azimuth mounts are the most basic type of mount, most commonly included with beginner telescopes.
On the other hand, if you are interested in getting into astrophotography, including capturing details of gaseous emissions, nebulae or small galaxies millions of light-years away, or other faint deep sky celestial bodies, an Equatorial mount is required. The main reason for this is to overcome something called field rotation.
Field rotation is the apparent rotation of celestial objects relative to the ground as they travel through the night sky.
Since equatorial mounts align with the Earth’s axis of rotation, they move along the right ascension axis without rotating the image captured on the camera’s sensor. In other words, they act like a star tracker that moves along with the apparent motion of the stars due to the rotation of the Earth.
You can think of an equatorial mount as an astrophotography mount, as this is their main benefit over alt-azimuth mounts.
If your astrophotography is 100% focused on planets that are incredibly bright in the night sky compared to deep-sky objects, then you could use an Altazimuth mount; however, there will be some drawbacks.
In summary, for photos, go for an Equatorial Mount, keeping in mind that you may want to switch your selection to the more straightforward Altazimuth mount if you’re only planning to take photos of planets.
If unsure but know you’ll be doing astrophotography, choose an Equatorial mount.
If there’s one thing for sure, you should choose the best mount you can afford and grow into it.
If your plans are for astrophotography, then getting an Equatorial Mount will be a good investment in your future astronomy plans.
QUESTION 2 OF 3: APERTURE SIZE
This question is specific to the Altazimuth category, and it’s a simple one.
You can use a regular alt-az mount if your telescope has a small aperture (less than 6 inches).
On the other hand, if you are planning on using a larger telescope (6 to 20 inches or larger), a Dobsonian mount might be better suited for you.
The main advantage of Dobsonian mounts over regular Altazimuth mounts is that they can handle larger telescopes. More details are in the section on Dobsonian mounts.
QUESTION 3 OF 3: TELESCOPE TYPE
This question is specific to the Equatorial category, and it’s also a simple one.
If your telescope is a reflector or refractor, choose a GEM (German Equatorial Mount).
If, on the other hand, your telescope is a catadioptric model, like a Schmidt-Cassegrain or Maksutov-Cassegrain, choose a Fork Mount.
The main advantage of a Fork Mount is that they are even more robust than a GEM and can handle the larger payload capacity of catadioptric telescopes, thanks to their “fork” design.
To summarize the above three questions, your basic telescope mount for visual astronomy is the alt-az mount.
If you’re planning for a large telescope, choose a Dobsonian mount, an altazimuth mount that can handle larger telescopes.
If you’re planning on doing astrophotography, choose an Equatorial mount. The GEM (German Equatorial Mount) is ideal for reflectors and refractors.
Choose a Form mount if you have an SCT (Schmidt-Cassegrain Telescope) or MCT (Maksutov-Cassegrain Telescope).
TYPES OF TELESCOPE MOUNTS: THE DETAILS
Now that you have a type of mount in mind, based on the above three questions, let me explain each telescope mount in detail.
I’ll dive into each mount in this section, including its advantages and disadvantages.
In subsequent sections, I’ll address frequently asked questions you might still have about specific mounts.
For now, let’s dive into each mount.
This mount allows the telescope to move in two directions: up and down (altitude axis) and left and right (azimuth axis).
Altazimuth mounts are simple and easy to use, making them popular for beginners. They are ideal for small telescopes.
Dobsonian mounts are also easy to use, simple, and low-cost.
The main design difference is that they are usually for large aperture telescopes.
The Dobsonian mount comes from its inventor, John Dobson, who developed the design in the 1960s to make large telescopes more accessible and affordable for amateur astronomers.
When fitting large telescopes (usually Newtonian reflecting telescopes) on Dobsonian mounts, they are called Dobsonian telescopes.
The Dobsonian mount consists of a sturdy base that sits on the ground and a telescope tube that mounts on a swiveling platform. The telescope points at an object in the sky by moving the platform in the desired direction. The platform can rotate in azimuth (left and right) and altitude (up and down).
A Dobsonian mount’s main advantages are its simplicity and low cost. It is relatively easy to build and maintain and requires no specialized equipment or electronics. Its simplicity makes it a popular choice for amateur astronomers who want to own a large telescope without breaking the bank.
Another advantage of a Dobsonian mount is its stability. The large, heavy base provides a solid foundation for the telescope, which helps to reduce vibrations and improve image quality. This stability is crucial for telescopes with long focal lengths, which are more sensitive to vibrations.
Despite its simplicity, a Dobsonian mount has some limitations.
It does not track the movement of objects in the sky, so you must manually move the telescope as the Earth rotates. Needing to move the telescope constantly can make it difficult to observe objects over long periods or to take long exposures for astrophotography.
An equatorial telescope mount tracks the movement of celestial objects in the sky due to the Earth’s rotation. Alignment to the Earth’s axis of rotation requires aligning the mount’s axis of rotation with the celestial pole, which is the point in the sky around which the stars appear to rotate.
There are two equatorial telescope mounts: German equatorial and fork equatorial.
GERMAN EQUATORIAL MOUNTS
German equatorial mounts have a single axis of rotation aligned with the celestial pole, and the telescope mounts on a slow-motion control rod that allows it to point at objects in the sky.
FORK EQUATORIAL MOUNTS
Fork equatorial mounts have two axes of rotation, one aligned with the celestial pole and the other perpendicular to it — the telescope mounts on a fork-shaped structure that allows it to point in any direction.
An equatorial telescope mount must first align with the celestial pole.
Once the mount is aligned, the telescope can point at an object in the sky by moving the mount in the right ascension and declination coordinates.
These coordinates are similar to longitude and latitude on the Earth. They are used to locate objects in the sky.
Many astronomers prefer equatorial telescope mounts because they allow the telescope to track the movement of objects in the sky, making it easier to observe objects over long periods.
They are also preferred for astrophotography, as they allow the telescope to move smoothly and accurately to take long-exposure photos.
ALTAZIMUTH MOUNTS: ADVANTAGES AND DISADVANTAGES
Altazimuth mounts are a type of telescope mount that allows the telescope to move in two directions: up and down (altitude) and left and right (azimuth).
ADVANTAGES OF ALTAZIMUTH MOUNTS
Here are the top advantages of Altazimuth mounts.
- They are simple in design and easy to use, making them a good choice for beginners.
- They are less expensive than other telescope mounts, such as equatorial mounts.
- They are lighter and more compact than other telescope mounts, making them easier to transport.
- They are suitable for a wide range of observing applications. You can use them for visual observations and short-exposure astrophotography (planets).
- Altazimuth mounts do not require polar alignment, which can be challenging for some users.
DISADVANTAGES OF ALTAZIMUTH MOUNTS
Here are the top disadvantages of Altazimuth mounts.
- They are challenging to use when wanting to track celestial objects. This difficulty makes them less suitable for long-exposure astrophotography or precise celestial observations.
- They are limited in tracking celestial objects because they only move in two directions relative to the ground. Equatorial mounts follow the movement of celestial objects in the sky using one “celestial” direction (right ascension).
- They are less stable than other mounts, making them less suitable for long exposures or high-magnification observations.
- They are unsuitable for heavy or large telescopes, as they may not support the instrument’s weight or size.
- They may be limited in their GoTo capabilities compared to other mounts, making it more difficult to point the telescope at specific objects in the sky.
DOBSONIAN MOUNTS: ADVANTAGES AND DISADVANTAGES
Dobsonian mounts are an alt-azimuth type of telescope mount that is simple, low-cost, and often used for large telescopes.
ADVANTAGES OF DOBSONIAN MOUNTS
Dobsonian mounts have the same advantages as regular altazimuth mounts. Below are their main advantages over regular altazimuth mounts.
- Dobsonian mounts are often used with large telescopes, providing a stable platform for these larger instruments.
- Dobsonian mounts can be mounted on any stable surface, making them versatile and easy to use.
DISADVANTAGES OF DOBSONIAN MOUNTS
There is only one additional disadvantage of Dobsonian mounts over regular altazimuth mounts.
- Dobsonian mounts may be heavier and larger than others, making them more challenging to transport and set up.
EQUATORIAL MOUNTS: ADVANTAGES AND DISADVANTAGES
Equatorial telescope mounts follow the movement of the sky as the Earth rotates, allowing you to track celestial objects smoothly and accurately with your telescope.
ADVANTAGES OF EQUATORIAL MOUNTS
Here are the top advantages of equatorial mounts.
- They follow the movement of the sky with great accuracy, making them ideal for long-exposure astrophotography and precise celestial observations.
- They are stable and can support long exposures, making them a good choice for deep-sky imaging.
- They are easy to polar align, which is essential for accurately tracking celestial objects.
- They are also suitable for visual observations because they allow you to follow a celestial object as it moves across the sky.
- Many equatorial mounts are compatible with GoTo systems, which allow the telescope to be pointed at specific objects in the sky at the push of a button.
- Many equatorial mounts can use automatic tracking systems to help compensate for the Earth’s rotation and improve tracking accuracy.
- Equatorial mounts are suitable for many telescope types, including refractors, reflectors, and catadioptrics.
DISADVANTAGES OF EQUATORIAL MOUNTS
Here are the top disadvantages of equatorial mounts.
- Equatorial mounts can be complex in design and may require more setup and maintenance than other mounts.
- They are more expensive than altazimuth mounts.
- They are usually heavier and larger than other mounts, making them more challenging to transport and set up.
- They require polar alignment to track celestial objects accurately, which can be challenging for some users.
- They require precise balance to work correctly, which can be challenging for some users.
- They may not be suitable for heavy or large telescopes, as they may not support the instrument’s weight or size.
FORK MOUNTS: ADVANTAGES AND DISADVANTAGES
Fork telescope mounts are a type of mount that consists of two arms that extend from a central base and support the telescope.
ADVANTAGES OF FORK MOUNTS
Fork mounts have the same advantages as regular equatorial mounts. Below are their main advantages over regular equatorial mounts.
- Fork mounts offer more versatility in terms of how to mount your telescope.
DISADVANTAGES OF FORK MOUNTS
There is only one additional disadvantage of Fork mounts over regular equatorial mounts.
- Equatorial Fork Mounts tend not to be as stable as German equatorial mounts.
WHY ARE EQUATORIAL MOUNTS BETTER FOR ASTROPHOTOGRAPHY?
For astrophotography, you should choose a stable mount capable of precise tracking.
Long exposures are required to capture faint celestial objects, and a mount that can accurately follow the movement of these objects across the sky will help to avoid blur and improve the overall quality of the image.
Equatorial mounts are required for astrophotography because they are designed to follow the movement of the sky with great accuracy and can support long exposures.
German equatorial mounts, in particular, can be very stable and precise, making them a good choice for this purpose.
Fork telescope mounts can also be good for astrophotography because they allow the telescope to move freely in all directions and can use computerized controllers and GoTo systems.
FOR WHAT PURPOSES SHOULD YOU USE AN EQUATORIAL MOUNT OVER AN ALTAZIMUTH MOUNT?
One main advantage of equatorial mounts is their ability to track celestial objects as they move across the sky accurately.
Their ability to track your target as to moves across the sky makes them a good choice for long-exposure astrophotography.
Equatorial mounts are also suitable for use with computerized controllers and GoTo systems, as they can follow the movement of the sky with great accuracy.
On the other hand, Altazimuth mounts are more complicated for tracking celestial objects, which makes them impractical for long-exposure astrophotography or precise celestial observations.
However, altazimuth mounts are generally more straightforward to use than equatorial mounts, which may make them a good choice for beginners or those who do not need the tracking accuracy of an equatorial mount.
Choosing between an equatorial mount and an altazimuth mount will depend on your specific needs and preferences.
Factors include the type of telescope you are using, your experience level, the observing you will be doing, and your budget.
ARE FORK TELESCOPE MOUNTS AVAILABLE FOR AMATEUR ASTRONOMERS?
Fork telescope mounts are available for amateur astronomers for mid-sized telescopes, such as Schmidt-Cassegrains or Maksutov-Cassegrains.
These mounts are known for their compact size, lightweight design, and ability to use computerized controllers and GoTo systems, making them a good choice for amateur astronomers.
Fork telescope mounts are more expensive than altazimuth mounts, but they offer several benefits that make them worth the extra cost for some amateur astronomers.
These benefits include improved tracking accuracy, the ability to use a wide range of telescope types, and the ability to mount on any stable surface.
IN TERMS OF WEIGHT CARRYING CAPACITY, WHICH TELESCOPE MOUNT IS WORST VERSUS BEST?
The weight-carrying capacity of a telescope mount refers to the maximum weight of the telescope and any other equipment that the mount can safely support.
The weight-carrying capacity of a mount will depend on its specific design and materials.
In general, equatorial mounts tend to have the highest weight-carrying capacity of all the types of telescope mounts that are commonly available to amateur astronomers. They are made of sturdy metal or aluminum to support heavy telescopes.
Equatorial mounts can typically support telescopes weighing up to several hundred pounds or more, depending on the specific design of the mount.
Altazimuth mounts tend to have a lower weight-carrying capacity than equatorial mounts, as they are generally more straightforward in design. However, some altazimuth mounts can still support relatively heavy telescopes.
Dobsonian mounts are a type of altazimuth mount specifically designed for large telescopes and often have a high weight carrying capacity. These mounts can typically support telescopes weighing up to several hundred pounds or more, depending on the specific design of the mount.
Fork telescope mounts are typically more lightweight than others and may have a lower weight-carrying capacity. These mounts are generally best suited for mid-sized telescopes, and the specific weight-carrying capacity of a fork telescope mount will depend on the specific design of the mount.
ARE THERE ANY MUST-HAVE ACCESSORIES FOR TELESCOPE MOUNTS?
Depending on your specific needs and preferences, several accessories can be helpful for telescope mounts. Here are a few examples of accessories that you may want to consider:
- Counterweights balance the weight of the telescope and other equipment on the mount. Counterweights help improve the mount’s stability and performance and can be especially useful for heavy telescopes or long-exposure astrophotography.
- Most telescope mounts install on a tripod or pier, which provides a stable platform for the mount to sit on. Choosing a high-quality tripod or pier can improve the stability and performance of the mount.
- Motor drives are devices to move the telescope automatically, allowing it to track celestial objects as they move across the sky. Motor drives can be handy for equatorial mounts, as they help to compensate for the Earth’s rotation.
COMPUTERIZED GOTO TELESCOPE MOUNTS
A computerized GoTo telescope mount is an equatorial mount that uses a built-in computer and motors to point the telescope at objects in the sky automatically.
These mounts use a system of coordinates, similar to longitude and latitude on Earth, to locate objects in the sky.
To use a computerized GoTo mount, you first input your location and the date and time into the mount’s computer. The mount then uses this information to calculate the position of the celestial objects in the sky. You can then select an object from a list of thousands of objects in the mount’s database, and the mount will automatically move the telescope to point at the selected object.
One of the main advantages of a computerized GoTo mount is its convenience and ease of use.
It is much easier to locate and observe objects in the sky with a GoTo mount than with a manual mount, as you don’t have to spend time searching for the object or calculating its coordinates.
Another advantage of a GoTo mount is its accuracy. The computer can move the telescope to a specific location in the sky with high precision, which helps observe faint objects or take long exposures for astrophotography.
There are some limitations to computerized GoTo mounts.
They tend to be more expensive than manual mounts and require a power source. They also require occasional maintenance, such as recalibrating the motors and updating the software. In addition, they may not be as precise as other types of mounts, such as equatorial wedge mounts for high-precision astrophotography.
MANUAL TRACKING VS. MOTORIZED
Manual tracking and motorized mounts are both types of telescope mounts to support a telescope and allow it to point at objects in the sky.
The main difference between the two is how they move the telescope to follow the movement of the objects in the sky.
A manual tracking mount is a type of mount that requires you to manually move the telescope to follow the movement of the objects in the sky.
Manual tracking mounts are usually simple in design and relatively low cost, but they can be time-consuming and require a lot of effort. You use a set of slow-motion control knobs or handles that allow you to make minor adjustments to the telescope’s position.
On the other hand, a motorized mount is a type of mount that uses motors to automatically move the telescope to follow the movement of the objects in the sky.
You select an object from a list of objects in the mount’s database, and the mount moves the telescope to point at the selected object.
Motorized mounts are more convenient and easier to use than manual tracking mounts, but they tend to be more expensive and require a power source.
HOW TO CHOOSE BETWEEN THE TWO?
MANUAL TRACKING MOUNTS
Manual tracking mounts are a good choice for those who want a simple, low-cost mount that allows them to control the telescope’s position manually.
Motorized mounts are a good choice for those who want a more convenient and easy-to-use mount that can automatically track the movement of objects in the sky.
You’ll need to bring a power source to your telescope setup, which might be a battery pack if you’re out in the field.
Polar alignment is aligning a telescope mount with the celestial pole, the point in the sky around which the stars appear to rotate.
Polar aligning is a crucial step when using an equatorial mount, as the mount’s axis of rotation must be aligned with the celestial pole to track objects’ movement in the sky accurately.
There are several methods for polar aligning a telescope mount.
The drift method involves pointing the telescope at a bright star and adjusting the mount until the star appears stationary in the eyepiece.
The polar scope method involves using a polar axis alignment scope, which is a small telescope mounted on the mount’s polar axis.
In the northern hemisphere, the scope sights Polaris, the North Star, located close to the north celestial pole.
The mount is adjusted until Polaris appears in the correct location inside the scope.
The celestial sphere method involves using a celestial sphere, a sky model showing the positions of the celestial objects.
The mount aligns with the celestial pole by rotating it until the celestial sphere aligns with the mount.
Polar alignment is essential in getting the most out of your telescope.
The accurate polar alignment will ensure that your telescope accurately tracks objects’ movement in the sky, which is vital for long-term observations and astrophotography.
This article presented three simple questions to help you choose the right telescope mount for your needs.
One of the four basic telescope mounts will best meet your needs.
Suppose your main interest is taking long-exposure photos with a DSLR camera or dedicated Astro-camera. In that case, your choice should be a German equatorial mount, a computerized mount that eliminates star trails as it rotates in the opposite direction of the Earth’s rotation.
FREQUENTLY ASKED QUESTIONS
WHAT IS THE MOST COMMON TYPE OF TELESCOPE MOUNT?
The most common type of telescope mount is the alt-azimuth mount. This mount moves the telescope up and down (altitude), left and right (azimuth). Alt-az mounts are simple to use, making them popular for beginner astronomers.
WHAT IS A GOTO TELESCOPE MOUNT?
A GoTo telescope mount is a type of mount that uses motors and computer control to automatically move the telescope to a specific location in the sky. GoTo mounts use a database of celestial objects, such as stars, planets, galaxies, and nebulae, and can accurately point the telescope at any of these objects on command.