Alt-Azimuth vs Equatorial Mount: Ultimate Comparison

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Written By: Zane Landers
Category: Learn

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Which Mount is Best for Me?

Equatorial mounts used to be seen as the only form of “serious” telescope mount, as telescopes used to have long tubes that shook in the wind or when adjustments were made, along with eyepieces with narrow fields of view requiring that the telescope be nearly perfectly centered on a target, so making fewer pointing adjustments was a huge plus. Today’s eyepieces have much wider fields of view, and the designs of alt-azimuth mounts have come a long way. Computerized pointing is also available for both equatorial and alt-azimuth designs. As such, the advantages of an equatorial mount are really only beneficial for astrophotography.

Many cheap tripod-mounted telescopes are less-than-steady due to low-quality tripods and often have lots of backlash and other issues in the mount. This is particularly true with cheap German equatorial mounts. You are not going to be doing long-exposure astrophotography with a German equatorial mount costing much less than ~$1,000 USD, so don’t choose your telescope based on the purported advantages of one of these mounts.

We strongly recommend Dobsonian alt-azimuth mounts to beginners. Manual fork or one-armed fork alt-azimuth mounts are great for refractors as well as smaller reflecting and catadioptric telescopes; however, a good alt-az mount can be somewhat expensive, and very cheap ones often have an outboard design, which makes aiming frustrating. Computerized or GoTo alt-azimuth mounts are not very necessary with smaller instruments, but they do add tracking.

Catadioptric telescopes of 8” or larger aperture usually have very long focal lengths and thus really need some kind of tracking and/or computerized mount, which can be either an alt-azimuth or equatorial design. The prime advantage of an equatorial mount with a larger Schmidt-Cassegrain telescope is that a GEM can be separated from the telescope tube and dismantled, whereas a computerized fork mount is heavy, bulky, and must be transported attached to the tube, which can be extremely difficult to do without help. However, an alt-azimuth fork is steadier, keeps the eyepiece more accessible, and is less complex to actually set up than a GEM. You can also convert many computerized alt-azimuth forks to an equatorial fork mount with a wedge for deep-sky astrophotography, though.

In general, we’d only recommend a German equatorial mount for larger refractors and Schmidt-Cassegrains or for deep-sky astrophotography. For everything else, the alt-azimuth mount design is king.

Which mount to choose between EQ and AltAZ

Telescope Mount Types

Telescope mounts come in two main configurations: altitude-azimuth (also known as alt-az) and equatorial.

An equatorial mount is a type of mount used for telescopes and sometimes cameras that allows the instrument to move in a way that follows the rotation of the Earth along a single axis, or right ascension, with the telescope’s right ascension axis pivoting east-west. An equatorial mount will track objects with a simple “clock drive” which spins the entire right ascension axis once over a 24-hour period, or simply by turning a fine-adjustment knob to move the telescope westward across the sky. The other axis, declination, adjusts pointing in the north-south direction.

An altitude-azimuth mount, on the other hand, is a type of mount that allows an instrument to move in two axes: altitude (up and down) and azimuth (left and right). This type of mount is simpler than an equatorial mount but requires constant adjustment in both directions, which must be varied depending on where the telescope is pointed. As such, alt-azimuth mounts can only track the sky if they have a computerized pointing system.

Even with motorized tracking, however, alt-azimuth mounts are difficult to use for long-exposure astrophotography as the target object will appear to flip on its side as the telescope tracks, and making automatic guiding adjustments for tracking accuracy is more difficult. Alt-azimuth mounts are generally used in conjunction with special tools like derotators for long-exposure astrophotography with very large telescopes of 16” or larger aperture where an equatorial mount would simply be too difficult to construct or house, and a derotator and other expensive measures are a better solution.

A third configuration, the “hybrid” equatorial mount, essentially an alt-azimuth mount that can be “tilted” into an equatorial configuration, also exists. Some of these mounts are very good (and also rather expensive), while many are sub-par. However, they may be the ideal fit for your needs. If not, you could always just purchase two separate mounts, since the dovetail bars most telescopes use to attach to a la carte mounts are interchangeable without tools.

Overall, an equatorial mount is more suitable for tracking objects in the sky over long periods of time for astrophotography, which is really the only reason to buy one, while an altitude-azimuth mount is more suitable for visual observations and is definitely what you want for your first telescope. Alt-azimuth mounts are cheaper, simpler, and easier to use than equatorial mounts if built to any decent standard of quality. Equatorial mounts are largely only necessary for telescopes where either an alt-azimuth mount would be impractical to transport in some way or if motorized tracking is required for astrophotography or some other purpose.

Alt-Azimuth Mount Types

Alt-azimuth mounts can come in a few configurations, each with different pros and cons.

  • Cheap Alt-Az Mounts

Many cheap alt-azimuth mounts are built exactly like a camera tripod, with the telescope suspended above the altitude axis and riding on a single pivot, often with no fine adjustments or sloppy ones at best. These mounts have to have the altitude axis locked or at least tightened when aimed above the horizon, or else they will simply allow the telescope to drift upward or even fall over. They are extremely annoying to adjust, and they are often shaky too. Avoid these mounts!

  • Fork Alt-Az Mounts

Fork mounts keep the telescope suspended between two pivots and are commonly seen with costlier computerized Schmidt-Cassegrain telescopes. One-armed fork mounts simply have a single pivot to move up and down, making them less sturdy for larger and heavier instruments. One-armed forks are also the type usually seen in well-designed manual alt-azimuth mounts. A typical manual one-armed fork keeps the telescope at the center of gravity on the altitude axis and has slow-motion adjustment cables for tracking and fine-pointing capabilities, much like a manual equatorial mount does. Manual alt-azimuth mounts are ideal for smaller tripod-mounted instruments, while GoTo alt-azimuth mounts are great with larger catadioptric telescopes, which need tracking and may be difficult to find objects manually on account of their long focal lengths.

  • Dobsonian Mounts: The Best-by-value Alt-Az Mount
Starsense 8" dob

If you’re on a budget, a Dobsonian telescope is best in lieu of small alt-azimuth-mounted refractors and reflectors.

The Dobsonian mount is named after its inventor, John Dobson, and is often used for large reflecting telescopes. It consists of an alt-azimuth mount that (ideally) has no clutches or gears. The design resembles a fork mount, but relies on friction and gravity rather than any gears or metal bearings. Instead, the telescope pivots using laminate on Teflon pads to glide smoothly up and down on large cylindrical bearings, spinning in azimuth with a laminate-covered bottom board riding on more Teflon.

The Dobsonian design is cheap to make, fairly lightweight, and compact, and the whole thing has a low center of gravity.

Unfortunately, most manufacturers do not follow the ideal design of the Dobsonian. Many commercial Dobsonians have too-small altitude bearings that require spring tensioning, clutches, a sliding tube, and/or counterweights to maintain balance and smooth motion, or are of one-armed fork designs. A lot of commercial Dobsonians’ altitude bearings also use inadequately sized Teflon pads, too-sticky laminate, or even just ditch the Teflon and laminate and ride a “lazy Susan” type roller bearing instead, which can be extremely frustrating to use, especially when trying to track at higher magnifications.

Dobsonians, even in their less-than-perfect forms, usually have smooth motions and are extremely easy to set up and use without the faults of sticky gearing, a wobbly tripod, or confusing GoTo computer systems, which make them ideal for beginner telescopes. For larger instruments, they are the only option for an economical, let alone portable, instrument for fantastic deep-sky observation.

It should be noted that the vast majority of the alt-azimuth mounts we “recommend” are Dobsonian mounts, which are built-in and supplied with their corresponding telescope. Additionally, many somewhat interchangeable alt-azimuth mounts end up being sold as one-offs or are not available a la carte. As such, we recommend you, as always, peruse our telescope rankings and consider the mounts supplied with each telescope individually. If you’re planning on deep-sky astrophotography, you need a hybrid or equatorial GoTo mount, and will need to look at those rankings instead.

The alt-az mounts available in hybrid configurations are listed further down in the “hybrid mounts” section of this article. Our full mount rankings list all alt-azimuth mounts, including hybrid ones, ranked by price categories.

The iOptron AZ Mount Pro is a beefy alt-azimuth mount with a side-by-side configuration, capable of holding dual telescopes up to 33 lbs and 13 lbs on each side, respectively. The AZ Mount Pro is rock solid, features the ability to be operated with a provided hand paddle or over WiFi, and its high-quality internal components will last a long time without maintenance or wear.

A manual alt-azimuth mount, the Explore Scientific Twilight I is a nifty, elegant unit capable of supporting a small telescope no heavier than about 15 pounds. The Twilight I can be adjusted with slow-motion cables on both the altitude and azimuth axis as well as locked in place with clutches, and sits atop a robust steel tripod. The Twilight I is perfect for small, wide-field telescopes or compact Maksutov-Cassegrains.

  • Sky-Watcher AZ5

The Sky-Watcher AZ5 is similar in design and weight capacity to the Explore Scientific Twilight I, but is not quite as well-made. However, it is a decent choice if, for some reason, Twilight I will not work for you.

Equatorial Mount Types

Sky-Watcher EQ6R/EQ6Ri Pro
SkyWatcher EQ6-Ri Pro EQ Mount

There are actually a huge variety of equatorial mount types, but most are variations on the same basic idea of either suspending the telescope in between the declination axis or outboard of it. The former is inherently less stable or portable, while the latter requires counterweights. 

Fork mounts “tilted” on a wedge – essentially an angled plate that converts an alt-az fork’s azimuth axis to a right ascension axis and altitude axis to declination – are the most common inboard design. The problem is that the telescope is inherently unstable with this configuration, as the often heavy drive base of the fork is placed at some point well outside the center of its pier or tripod. Additionally, the right ascension axis has a huge amount of weight bearing down on it at an angle, as it rests on only a single pivot point. 

If you were to extend the equatorial forks so that they met again at some point above the telescope tube at a second pivot point, you’d have an English yoke mount. The English yoke mount is actually a really clever design, but it’s not portable, and the top of the right ascension axis means the telescope can’t point near the north celestial pole. Enlarging the top bearing and cutting a hole in it produces the horseshoe mount design, which has been used for many older research telescopes like the 200” Hale telescope. Horseshoe designs are sometimes seen in semi-portable amateur telescopes but are uncommon as they are complex to construct and still rather bulky.

Equatorial mounts with the telescope on the outside of the declination axis are inherently more portable than inboard designs and also make it much easier to interchange different telescopes on the same mount. The downside is that they require counterweights and often put the eyepiece in an uncomfortable position if you’re looking through the telescope. The height and angle of the eyepiece vary enormously, and you almost certainly will have to rotate the telescope tube (or star diagonal) in its rings to comfortably place the eyepiece, depending on where you are aimed in the sky. 

Occasionally, designs such as the inverse fork and cross-axis English yoke mount are built, but the only one you’re likely to ever see is the German equatorial mount, or GEM. German equatorial mounts are fairly simple in construction and allow easy use atop tripods, as well as the installation of a miniature telescope through the center of the right ascension axis to aid in accurate polar alignment.

To see the EQ mounts that are available in a hybrid configuration, scroll down to the “hybrid mounts” section. Our Mount Rankings goes over all of the hybrid and classical German equatorial mounts available today, sorted by price and ranked in performance/value, while we also have a Top Equatorial Mounts article for you to peruse.

A top-of-the-line German equatorial mount, the Losmandy G11 is convertible to a lighter or heavier duty unit as the G811 or G11GT, respectively. The G11 is available with either the Gemini II or PMC-Eight control units and features extremely accurate tracking and guiding, smooth manual adjustments, and a top-quality build, with a weight capacity of ~55-60 lbs for visual use and 35-40 lbs for astrophotography, all in a fairly portable and collapsible form factor.

The Sky-Watcher EQ6Ri Pro is an impressive German equatorial mount with a huge 44-lb payload capacity and a remarkable set of high-quality features for its price. It can be controlled via WiFi by default, or with a plugged-in SynScan hand controller or PC cable. The EQ6Ri is ideally suited for deep-sky astrophotography use with 8” SCTs, Newtonians, or Ritchey-Chretien telescopes, as well as 4-5” refractors, while it can hold even the largest Schmidt-Cassegrains with ease for visual observation.

Much like the EQ6Ri Pro and with largely the same set of features (albeit scaled down), the Sky-Watcher HEQ5i Pro reigns supreme in its price and weight capacity range. This mount is ideal for beginner astrophotographers, and can hold medium-sized (up to ~20lb) telescopes for visual observation too. For astrophotography, small refractors or up to 6” Newtonian/Cassegrain telescopes are ideal for use with the HEQ5i Pro without running into tracking or stability issues. The Orion Sirius EQ-G is identical to the HEQ5 in every way, if you happen to come across one.

The EQM-35i, with its lightweight design and affordability, is an excellent choice for those venturing into astrophotography. Despite its lower price point, it maintains full compatibility with autoguiders, PC control software, and other essential imaging tools, much like its more expensive Sky-Watcher counterparts.  For those not worried about exceeding its capacity, the Sky-Watcher EQM-35 serves as a cost-effective choice for an astrophotography mount, though for visual purposes it is only capable of holding small (<15lb) telescopes, and for astrophotography its weight capacity is less than 10 lbs, including all accessories you might put on your telescope.

Essentially a stripped-down EQM-35i with no electronics and a 15-20 lb weight capacity, the Celestron CG-4 is a cheap but well-made German equatorial mount with few plastic parts. It’s ideal for visual observers, and a dual-axis drive kit can be added for tracking and small motorized pointing adjustments if needed. However, a simpler alt-azimuth mount may be a preferable choice for this job.

Hybrid Mounts

Sky-Watcher AZ-GTi hybrid mount

A few alt-azimuth mounts that can be converted to equatorial configurations exist. These broadly fit into two categories. The first is the computerized fork-mounted Schmidt-Cassegrain telescopes from Meade and Celestron, which can be converted to an equatorial configuration with a wedge – older manual units require a wedge as they will only track in the equatorial configuration. The wedge and fork mount designs are rarely as accurate or easy to set up as a German equatorial mount for astrophotography, and any other purpose will be just fine utilizing GoTo for tracking in the alt-azimuth configuration. Wedges are expensive and add to the weight, height, and complexity of assembling your telescope, so if you can avoid using one with a GoTo telescope, it is usually the right choice to do so.

The other type of hybrid mount is newer. Sky-Watcher, ZWO, iOptron, Losmandy, and others market mounts that can be converted to an alt-azimuth side-by-side (inverse fork, technically) configuration mount to hold one or two telescopes and then tilted to become a German equatorial mount. The vast majority of these are GoTos, and many are often based on quality astrophotography mounts. If you have the money and want additional versatility for your equatorially-mounted setup, by all means go with a hybrid mount. However, you may not need an expensive hybrid mount if you are just using a small telescope for visual observation purposes.

The Sky-Watcher AZ-EQ6i shares the same basic features and capacity as the EQ6Ri German equatorial, but can be converted to an alt-azimuth mount. It is also equipped with Sky-Watcher’s FreedomFind technology, which allows for manual aiming. This feature is particularly useful at outreach events where there’s concern about minor bumps or when time is of the essence and you don’t want to bother with the electronics. The AZ-EQ6i can support one or two telescopes in its alt-az configuration. By default, the mount is controlled over WiFi, but a version with the SynScan hand controller is available, and you can always purchase the corresponding accessory for either.

Like its larger sibling, the AZ-EQ6i, the AZ-EQ5i is a hybrid alt-az/German equatorial with FreedomFind encoders, a WiFi-based control system using the SynScan app. It is also able to support two telescopes in its alt-az configuration. Unlike the AZ-EQ6i and EQ6Ri Pro, however, the AZ-EQ5i has significant advantages over the HEQ5i Pro, such as a more compact form factor, belt drives for astrophotography, and a supplied pier extension, which make it worth seriously considering even if you plan to only use it in the equatorial configuration.

The Sky-Watcher AZ-GTi is an alt-azimuth GoTo mount with FreedomFind encoders operated over the SynScan app, much like the larger hybrid Sky-Watcher mounts. However, the AZ-GTi is not quite as easily converted to equatorial mode, requiring a software update and aftermarket hardware purchases for the job. The AZ-GTi is made for small telescopes or camera lenses, and easily breaks down to fit into a backpack, while it can fit on any tripod with a ⅜” stud at the top, including the lightweight one supplied with the mount

Zane Landers

An amateur astronomer and telescope maker from Connecticut who has been featured on TIME magazineNational GeographicLa Vanguardia, and Clarin, The Guardian, The Arizona Daily Star, and Astronomy Technology Today and had won the Stellafane 1st and 3rd place Junior Awards in the 2018 Convention. Zane has owned over 425 telescopes, of which around 400 he has actually gotten to take out under the stars. These range from the stuff we review on TelescopicWatch to homemade or antique telescopes; the oldest he has owned or worked on so far was an Emil Busch refractor made shortly before the outbreak of World War I. Many of these are telescopes that he repaired or built.

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