Harmonic drive mounts have quickly become some of the most sought-after options in the astrophotography community, and for good reason. Their unmatched payload-to-weight ratio and ability to be used without a counterweight have opened new possibilities for both beginners and advanced imagers alike. ZWO’s AM5 was an absolute success within the astrophotography community, as was the compact AM3. Now we have the AM3N, an iteration that builds on the success of the AM3 with new features, upgrades, and quality-of-life improvements that follow in the footsteps of the improved AM5N.
In this review, we’ll take a closer look at the AM3N’s design, upgrades, and most importantly, how it performs under the stars when paired with a modern imaging rig.
Specifications & Design
The AM3N follows ZWO’s familiar aesthetic with its beautiful anodized ZWO-Red finish, easy-to-adjust hardware, and compact form factor. At just 9 lbs, this mount head is impressively lightweight yet capable of handling serious payloads:
- Payload Capacity: 28 lbs with counterweight, 18 lbs without
- Weight: 9 lbs (mount head only)
- Mount Modes: Equatorial or Alt-Azimuth
- Saddle: Dual Vixen / Losmandy-style
- Mount-Head Ports: 12V DC power port, USB port, hand controller, ST-4, Bluetooth indicator
With this payload, the AM3N can handle more than just small refractors. Medium-sized APOs, like a 90mm triplet, and even up to 103mm class refractors, are all great options that work without a counterweight. When paired with a lightweight tripod and imaging accessories, the total weight of an imaging rig like this sits at around 23-25lbs, making it an ultra-portable deep-sky rig!
New Features & Upgrades
As you can see above, much of the AM3N remains the same as the original, such as the anodized red coating, the small and compact footprint, and the easy-to-adjust hardware. These are all characteristics we all expect to see from iteration to iteration. But ZWO has added several key upgrades that take this mount to the next level:
Click to Enlarge Image
Click to Enlarge Image
- Powered Declination Hub: A fully powered DEC saddle with USB-C and 12V power output simplifies cable management. This allows for 360° tangle-free rotation, preventing dreaded cable snags that typically occur when cables hang over to the RA axis.
- Bluetooth Control: The AM3N can now connect wirelessly to the ASIAIR and ZWO cameras via stable Bluetooth. This eliminates the need for a USB-C connection between the mount and the controller.
- Wide Temperature Range: Now rated from -4°F to 104°F, the AM3N is built to perform in both extreme cold and summer heat.
- Magnetic Hex Key: Included for quick adjustments of the alt-az knobs and tripod plate for easy adjustment during colder temperatures when your fingers just don't want to cooperate.
Field Testing the AM3N
For our test, we paired the AM3N with a 90mm APO triplet refractor, ZWO 2600MC Air, ZWO EAF Pro, and the ZWO Camera Angle Adjuster.
Guiding performance was consistently excellent. Over several hours of imaging, the AM3N maintained a total RMS error between 0.35”–0.50”. If you are at all familiar with autoguiding, you may know the rule of thumb that your RMS error should be about ½ of your imaging resolution. With a conservative, widefield setup like ours, we were sitting at 1.43”/pixel, and we are well within that range.
Final Thoughts
The new powered DEC hub worked exactly as intended: cable management was simplified, and we experienced zero tangles or interruptions during meridian flips. Bluetooth connectivity also proved reliable, allowing full control through the ASIAIR without the need for a physical mount-to-camera connection. This mount combines portability, reliability, and modern cable management into a streamlined package that integrates perfectly with ZWO’s ecosystem of cameras and accessories. Whether you’re a beginner looking for your first serious mount or an experienced astrophotographer seeking a travel-friendly rig, the ZWO AM3N is a top-tier option that makes the most of every clear night.
Learn More
Interested in diving deeper into the world of astronomy? Check out our AstronomyHub for a wealth of articles, guides, local resources for planetariums and observatories near you, and more to enhance your stargazing experience.
