Celestron CGX Equatorial Mount Reviewed

The Celestron CGX is Celestron’s newest heavy payload computerized equatorial mount and is in a way the successor to the Celestron CGEM Mount, and boy is it much more successful compared to the CGEM! TheCGX’s design is improved, based on the mistakes that Celestron made with its previous CGEM and AVX mounts.

The CGX is a much heavier payload mount than the CGEM, and is far more reliable and autonomous than the CGEM which is great for astrophotographers and visual observers alike. The CGX seems to be Celestrons’s competitor to the Skywatcher EQ6-r mount, however, it is quite different to the EQ6 type mounts that astronomers have come to know and love, but that may be a good thing as we are finally breaking free of the limitations of the EQ6 design.

The CGX is mostly intended for astrophotography as many of its new features I will discuss in the review are greatly beneficial, however, you are still definitely able to use the CGX for visual observing. Is the CGX Celestron’s first truly great astrophotography mount that has surpassed the level of quality found in earlier mounts?  That’s what I will be discussing today.

Technical Specs of Celestron CGX

The Celestron CGX, while being a new, innovative design in the world of astrophotography mounts, still does share some features with its EQ6 style predecessors and as such there are still some basic tech specs that you should know.

• The CGX has a weight capacity of 55 lbs or 25 kilograms, which is far improved over the EQ6-R or CGEM, being 5 and 7kg more respectively. This means that you will be able to load the CGX up with far more weight and still have good guiding, however, this number can sometimes be difficult to interpret. 
• Unfortunately, Celestron along with most mount manufacturers are not very specific as to how much weight on the mount is acceptable for specific purposes and how it affects the tracking and guiding accuracy of the mount. It is commonly accepted amongst astronomers that if you are doing visual observing you can load up the mount to the weight limit or even exceed it by a few kgs, as fast small scale errors are not very noticeable visually.
  • In contrast, when you are taking images the mount’s tracking accuracy has to be far more precise because the images you take will show streaking easily. Adding more weight onto the mount can increase the magnitude of tracking errors and ruin any images you would take.
  • For this reason, I along with other astrophotographers recommend using up to ⅔ the supposed weight capacity for astrophotography. It is important to keep in mind this is a very broad statement, and tracking/guiding accuracy depends on many factors which are too long to list here.
• The mount accepts both Vixen (narrow style) and Losmandy (wide style) dovetails, an improvement over the CGEM, which allows you to use any telescope that has a standard mounting system with the CGX, provided you can balance the mount with enough counterweights and keep the weight on the mount under around 25 kilograms.
• The CGX also includes a Nexstar+ hand controller. It is the standard hand controller used across all of Celestron’s computerized mounts. It includes over 40,000 objects with Messier, NGC, IC and custom coordinates for finding any target in the sky that you choose.
• The CGX weighs 20 kilograms, not including the tripod which is also somewhat heavy at 8.7kg. This can be somewhat of a problem for people who want to use the mount, as 20 kilograms is quite heavy, but this is necessary for the mount to withstand strong wind gusts and vibrations while keeping images sharp. I find that if you get a good grip on the mount, it isn’t too hard to move.

Best Features

The CGX is packed full of new features and overall improvements compared to other mounts. Celestron listened to the user base and remedied many of the issues and concerns found with mounts like the CGEM and AVX, not to mention new and improved features which I will now list.

• The CGX comes with belt-driven and spring-loaded worm drives, an incredible upgrade over the CGEM and will greatly improve guiding accuracy.
  • Mounts like the EQ6 and CGEM use gears to connect the motor to the worm drive (the most important gear you will find in a mount), which can create problems where too much space is between the gears, causing an issue called backlash.
  • Backlash can be seen during guiding. It effectively makes some guide pulses ineffective, as any corrective action is stuck in the gap between gear teeth.
  • A belt drive cuts out the middle gear and instead connects the motor to the worm gear with a toothed belt which eliminates all backlash.
  • The worm gear is also spring-loaded, which ensures it is well tensioned. This also reduces backlash and makes adjusting spacing manually not necessary.
  • Luckily the CGX comes with belts preinstalled, whereas in mounts like the EQ6 and AVX belts were something you had to install manually, and worse in the CGEM you had no option to install belts at all.
• The CGX features a homing system. This is a system where the mount can locate its “home” position without any external input, which is where the mount rests when not pointing to anything.
  • Homing moves both mount axes (Right Ascension and Declination) automatically to their home position without any sort of outside input.
  • This is particularly useful for observatory systems where the mount is permanently polar aligned, yet you may not have access to the mount. With Homing you would be able to be sure of the mount’s positioning without something like plate solving or star alignment.
  • Homing is a rarely seen feature in mounts at this price point and is a premium feature found in the CGX, sure to make the lives of astrophotographers easier.
• The CGX features a completely new, redesigned polar alignment base plate.
  • In the CGEM, when you tried to adjust the azimuth polar alignment the mount would stick and skip, making it impossible to align the mount closely to the celestial pole.
  • The new and improved polar alignment plate is greatly improved, lowering the amount of friction between the mount head and tripod. It also features improved adjustment knobs which make alignment far easier than with the awkward, circular knobs found on the CGEM.
  • The mount is also able to go all the way down to 3 degrees latitude and a maximum of 65 degrees, which allows you to use the mount in locations very close to the equator and very far from it.

The CGX for Astrophotography

The CGX, of course, is Celestron’s best astrophotography mount yet. There are some features listed above that make this an excellent mount on the inside, but the CGX also includes some great features that make the mount a joy to use in the field.

The CGX has full computer control and support, based on the new Celestron PWI software/interface. The PWI software allows you to completely bypass the hand controller, which becomes an unnecessary step when you are doing deep space astrophotography. With PWI, the time-consuming step of entering the time and date into the hand controller is not necessary either. This is thanks to the CGX’s included USB type B port, which allows you to connect directly to the mount without hand controller or adaptors – just get the suitable cable and you are good to go.

Celestron PWI is a fully functional planetarium software which is built around CGX support. Using this software you can see in real-time where the mount is pointed. It also allows you to update the mount’s positioning model without having to do any star alignment via plate solving.

Luckily, the PWI is also ASCOM compatible (ASCOM is an open-source program which allows devices to communicate with software), which means the mount is controllable with any standard image capture programs, for example, SGP, NINA, APT and other similar programs which you can use to plate solve (align your mount via images of stars), slew to various targets and perform meridian flips automatically.

Thanks to many new features and improvements, the CGX is an excellent performer in the field regarding guiding accuracy, which is sure to make your images look excellent without streaking. Thanks to the easy computer connectivity you can slew around with ease, without ever even having to use the hand controller.

The CGX for Visual Observing

The CGX mount is sure to make visual observing a joy. The mount uses the Nexstar+ hand controller, which is in my opinion superior to the Skywatcher/Orion alternatives as it is easier to use, which becomes an important factor late at night.

The Nexstar+ hand controller also includes over 40,000 objects in its database, an internal time clock which means that you do not have to enter the time and date every time you start up the mount if you choose to enable it. The pointing accuracy of the mount after a 3-star alignment is also excellent. The controller includes 9 slew rates for intricate and accurate slewing and pointing which means you can go from rate 9, which moves the mount several degrees per second to 1, moving at half the speed of the stars.

The Nexstar+ also includes a red backlight, which lights up the text on the hand controller without ruining your night vision, meaning you can slew the mount around with ease at night.

The mount includes a built-in polar alignment feature/routine which is incredibly useful for visual observers. It calculates your alignment error based on your three-star alignment, which is incredibly useful for observers who do not want to use the polar scope, or those who have no clear view of the celestial pole.

The mount can take a very high amount of weight for visual but that also means that the mount itself is fairly heavy. This becomes a major issue that you will have to think about if you want a mount with such a high payload capacity like the CGX.

Conclusion

In conclusion, I believe that the CGX is Celestron’s first truly excellent mount that caters to almost everyone willing to purchase it and deal with the fairly heavy mount. It performs excellently for astrophotography with numerous improvements “under the hood” but also many features in software and hardware that make the mount great for imaging with high accuracy.

For visual the mount includes the Nexstar+ that visual observers have come to know and love, with its polar alignment features and internal timekeeping. Overall, in my opinion, if you have the budget to go for the CGX mount, then I would highly recommend you do as it is sure to last you for a long time and produce excellent images and great observing nights.