ioptron gem45 vs cem40 review

iOptron GEM45 vs CEM40 Review

Astrophotography enthusiasts know that the quality of the mount is just as important as the telescope and camera used. A high-quality mount ensures that the telescope remains stable during long exposures, resulting in clear and sharp images. Two mounts that are highly regarded in the astrophotography community are the iOptron GEM45 and the iOptron CEM40.

In this article, we will compare these two mounts in terms of features, specifications, and user experience, to help you make an informed decision about which mount is best suited for your astrophotography needs.

iOptron GEM45

The iOptron GEM45 is a German equatorial mount that offers a payload capacity of up to 45 pounds (20.4 kg). It features a Go2Nova 8407 hand controller with a database of over 359,000 celestial objects, making it easy to find and track your desired target. The mount also includes a built-in iPolar electronic polar scope, which provides accurate polar alignment in just a few minutes.

One of the standout features of the iOptron GEM45 is its AccuAligning system, which uses a digital level sensor and an electronic fine-tuning system to achieve perfect alignment. This feature ensures that the mount is perfectly aligned with the celestial pole, resulting in more accurate tracking and better image quality.

iOptron CEM40

The iOptron CEM40 is a center-balanced equatorial mount that offers a payload capacity of up to 40 pounds (18.2 kg). It features an advanced control system that includes an advanced electronic polar scope (AES), which provides highly accurate polar alignment in just a few minutes.

The CEM40 also includes a built-in WiFi module, which allows you to control the mount using your smartphone or tablet via the iOptron StarFi app. This feature provides a convenient and intuitive way to control the mount, especially when you are working alone in the field.

Another standout feature of the iOptron CEM40 is its patented non-contact magnetically loaded gear system, which eliminates the need for traditional gears and reduces backlash. This system ensures smooth and accurate tracking, even at high magnifications.


When comparing the iOptron GEM45 and CEM40, there are several similarities and differences to consider. Both mounts offer a high payload capacity, advanced polar alignment systems, and smooth tracking. However, there are some key differences between the two mounts.

One of the main differences is the type of mount. The GEM45 is a traditional German equatorial mount, while the CEM40 is a center-balanced equatorial mount. This difference in design affects the overall stability and ease of use of the mount.

The GEM45's AccuAligning system provides a more accurate polar alignment than the CEM40's AES system. However, the CEM40's WiFi module and StarFi app provide a more convenient and user-friendly control system than the GEM45's hand controller.

Another significant difference between the two mounts is the price. The iOptron CEM40 is typically more expensive than the iOptron GEM45. This difference in price may influence which mount is best suited for your budget and astrophotography needs.


In conclusion, the iOptron GEM45 and CEM40 mounts are both excellent options for astrophotographers and astronomers. The GEM45 offers a more traditional German equatorial mount design, with a sturdy build and accurate tracking. It is a good choice for those who prefer a classic design and want a reliable mount for their astrophotography needs.

On the other hand, the CEM40 offers a unique center-balanced design that provides more stability, easier balancing, and smoother tracking. It also features advanced features like iPolar alignment and a built-in GPS system. This mount is ideal for those who want a more modern design and advanced features for their astrophotography.

Ultimately, the choice between the iOptron GEM45 and CEM40 will come down to personal preferences and specific astrophotography needs. Both mounts have their unique strengths and benefits, and either one can be an excellent choice for capturing stunning images of the night sky.

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