German Equatorial Mounts - Go To

German equatorial mounts or GEMs track an object using constant speed movement on one axis that is oriented parallel to the Earth's axis of rotation. This makes the design ideal for astrophotography. They are often preferred by planetary observers for their ability to precisely track an object at very high magnifications. The more advanced German equatorial mounts include Periodic Error Correction (PEC), or permanent PEC, a computer algorithm that compensates for minor flaws in the tracking gear train.

The image at right depicts a German equatorial mount with a refractor telescope. The telescope and counterweight rotate about the right-ascension axis, which must be oriented parallel to the Earth's axis of rotation. The counterweight is used to balance the weight of the telescope and other instruments or accessories such that the telescope can track and slew with minimal power consumption and strain on the motor. The telescope also rotates about a second axis, known as the declination axis, which is perpendicular to the right ascension axis. Balance on this axis is achieved by moving the telescope within its mounting rings, or by moving the entire telescope and ring assembly in the mount saddle along the mating dovetail bar.

Alignment of the right-ascension axis with the Earth's axis of rotation is more commonly referred to as polar alignment. Residents of the norther hemisphere are fortunate to have a reasonably bright star near the celestial pole. The north star Polaris is located about two thirds of one degree from the true celestial pole. Most but not all German equatorial mounts are equipped with a sight tube through the middle of the right ascension axis. Rough polar alignment is achieved by sighting Polaris through this tube. A rough polar alignment is generally good enough for visual observing, but a more precise polar alignment is required for astrophotography. This can be achieved using a polar alignment scope, software assisted methods embedded in the on-board computer systems of some go-to German equatorial mounts, or a combination of these techniques.

  • Celestron Advanced VX Mount
  • Celestron Advanced VX Mount

  • Celestron Advanced VX Mount - an affordable EQ mount that was engineered from the ground up with astro imaging in mind. read more...
  • Our price: $899.00

  • Celestron CGEM II Mount
  • Celestron CGEM II Mount

  • The Celestron CGEM II mount is an evolution of the original Celestron CGEM mount, with a 40-pound instrument capacity and a number of new features and upgrades. read more...
  • Our price: $1599.00

  • Celestron CGX Mount
  • Celestron CGX Mount

  • The newly designed Celestron CGX mount offers a number of advancements in capacity and performance vs. previous generation mounts. read more...
  • Our price: $2199.00

  • Celestron CGX-L Mount
  • Celestron CGX-L Mount

  • CGX-L is Celestron's largest and most capable computerized German equatorial mount in a 75 pound instrument capacity. read more...
  • Our price: $3499.00

  • Sky-Watcher AZ-EQ5 Mount
  • Sky-Watcher AZ-EQ5 Mount

  • The Sky-Watcher AZ-EQ5 Go To mount is equally useful as a German equatorial or alt-azimuth mount. read more...
  • Our price: $1385.00

  • Sky-Watcher EQ6-R Pro
  • Sky-Watcher EQ6-R Pro

  • The Sky-Watcher EQ6-R Pro features belt drive and a 44 pound instrument capacity. read more...
  • Our price: $1595.00

  • Losmandy G11 Equatorial Mount with Tripod
  • Losmandy G11 Equatorial Mount with Tripod

  • This Losmandy G11 mount combines the Explore Scientific open source PMC-Eight go to controller with the highly acclaimed Losmandy G11 equatorial mount with a tripod capable of supporting 60 pounds. read more...
  • Our price: $3399.99

  • Losmandy G11GFT Mount
  • Losmandy G11GFT Mount

  • The Losmandy G-11 mount is a high-quality German equatorial mount with a 60-pound instrument capacity. read more...
  • Our price: $3295.00

  • Losmandy GM811G Mount
  • Losmandy GM811G Mount

  • Losmandy GM811G German equatorial mounts feature a 50 pound instrument capacity and the Gemini 2 Go To system. read more...
  • Our price: $2795.00

  • Losmandy GM811GHD Mount
  • Losmandy GM811GHD Mount

  • This mount is nearly identical to the Losmandy GM811G but comes equipped with the heavy duty folding tripod. read more...
  • Our price: $2995.00

  • Losmandy GM8G Mount
  • Losmandy GM8G Mount

  • The Losmandy GM8G is a high quality German equatorial mount with a 30 pound instrument capacity, lightweight folding tripod, and Gemini 2 go to system. read more...
  • Our price: $2495.00

  • Orion Sirius EQ-G Mount
  • Orion Sirius EQ-G Mount

  • The Orion Sirius EQ-G is a capable mount for both visual and photographic applications. read more...
  • Our price: $1199.00

  • Orion Atlas EQ-G Mount
  • Orion Atlas EQ-G Mount

  • The Orion Atlas EQ-G is our favorite mount for astrophotography in the sub $1500 class. read more...
  • Our price: $1499.00

  • Orion Atlas Pro AZ/EQ-G
  • Orion Atlas Pro AZ/EQ-G

  • The Orion Atlas Pro AZ/EQ-G mount operates in both equatorial and altazimuth modes, making it an ideal one mount solution for those who enjoy both astrophotography and visual observing. read more...
  • Our price: $1999.00

  • Orion HDX110 EQ-G GoTo Equatorial Mount
  • Orion HDX110 EQ-G GoTo Equatorial Mount

  • This configuration of the Orion HDX110 EQ-G mount is intended to be mounted in a permanent observatory on a user supplied pier. It includes the mount head, case and counterweight shaft. Tripod pier and counterweights not included. read more...
  • Our price: $3299.00

  • Orion HDX110 EQ-G GoTo Equatorial Mount with Tripod Pier
  • Orion HDX110 EQ-G GoTo Equatorial Mount with Tripod Pier

  • The Orion HDX110 EQ-G mount supports up to 110 pounds of instruments and provides smooth plus or minus 3 arc-second tracking accuracy. read more...
  • Our price: $4199.00

  • Meade LX850 German EQ Mount w/Starlock
  • Meade LX850 German EQ Mount w/Starlock

  • Meade LX850 German equatorial mount with built in StarLock autogiding system. read more...
  • Our price: $6199.00

  • iOptron SmartEQ Pro
  • iOptron SmartEQ Pro

  • If you intend to use a Smart EQ mount for AstroPhotography. The Smart EQ Pro may be the better choice. read more...
  • Our price: $499.00

  • iOptron iEQ30 Pro w/ Tripod
  • iOptron iEQ30 Pro w/ Tripod

  • Introducing the NEW iEQ30 Pro!--- the next in the iEQ Series of high-performance, portable equatorial mounts. The iEQ30 Pro offers the next generation GoTo technology from iOptron read more...
  • Our price: $1198.00

  • RRP: $1299.00
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  • iOptron iEQ45 Pro with Tripod
  • iOptron iEQ45 Pro with Tripod

  • The iEQ45 Pro is an improved version of this equatorial mount with 45 pound instrument capacity. read more...
  • Our price: $1698.00

  • iOptron iEQ45 Pro with Tripod and Hard Case
  • iOptron iEQ45 Pro with Tripod and Hard Case

  • The iOptron #8000E-HC package includes the new iEQ45 Pro mount, tripod and a hard case for storage and transport of the mount head. read more...
  • Our price: $1798.00

  • iOptron CEM60
  • iOptron CEM60

  • The iOptron CEM60 is a new concept in equatorial mounts that places the payload at the center of gravity allowing for greater natural stability. read more...
  • Our price: $2188.00

  • iOptron CEM60-EC
  • iOptron CEM60-EC

  • 7201 iOptron CEM60 Center Balanced Equatorial Mount with High Precision Encoder read more...
  • Our price: $3498.00

German Equatorial Mounts

German equatorial mounts, also known as GEMsprovide a stable foundation for both astrophotography and celestial observation.

German equatorial mounts are defined by their movement, which pivots around an axis aligned with the earth’s rotation axis. While this type of movement is less intuitive and slightly more awkward for traditional viewing, it’s essential for astrophotography for its ability to track an  object without field rotation. German equatorial mounts are easily identified by their counterweight, which is used to balance the telescope across the primary axis of the mount, or polar axis, resulting in greater stability and weight capacity.

Movement of German Equatorial Mounts

German equatorial mounts make use of two axes: right ascension and declination. The right ascension or polar axis is the primary axis of the mount and is aligned toward the north celestial pole near Polaris, the north star. Since Polaris is a relatively fixed point in space located only two-thirds a degree away from the true celestial pole, rotating around an axis aligned to Polaris allows the visual observer to follow objects more easily. Astrophotographers will align to the true celestial pole for the best possible tracking.

The declination axis, however, is the axis the counterweight shaft. Movement on the declination axis allows for adjustments perpendicular to the polar axis. Movement around the polar axis allows for east and west movement in celestrial coordinates, while movement around the declination axis goes north and south.

German Equatorial Mount Features

A few more common features to consider include:

  • PEC: The PEC system automatically corrects these errors in the computerized equatorial mount as the mount tracks an object across the night sky, making for a smoother and more accurate tracking of the target. This is particularly important for long exposure Astrophotography.
  • Polar Alignment: Alignment with the celestial pole is essential for proper use of a German equatorial mount, which is why most are equipped with a sight tube through the middle of the declination axis or an alignment software system. The best astrophotography mounts may use a combination of both.

The motions necessary to locate an object using a German equatorial mount can be baffling to beginners. For that reason, we make it a rule to never recommend such mounts for young children. Our fellow amateur astronomer Jeff DeTray has published an online EQ mount tutorial that is complete with animated examples of how these mounts move. This recommended reading for first time German equatorial mount buyers, even if you are considering a go-to mount.

If you’re considering purchasing a German equatorial mount of your own or are wondering which is the best telescope mount for astrophotography, Skies Unlimited can help. We’re committed to providing you with high quality German equatorial mounts, along with the advice you need to use them correctly.

Founded in 2004 by real amateur astronomers, Skies Unlimited was started with the goal of making amateur astronomy easier and more accessible for the masses with practical knowledge and quality products. That’s why we employ a team of amateur astronomers with years of personal and professional knowledge in the field — any one of our team members can give you advice backed by both personal and professional experience. Call Skies Unlimited today or visit our Pottstown, Pa., location to get started on your next purchase.


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