iOptron GEM45EC Equatorial Mount Head with Hard Case – Precision Engineering, Lightweight Design, and Sub-Arcsecond Tracking
A premium portable mount head for imagers and visual observers who demand more—now with high-resolution encoder tracking and included hard case.
The iOptron GEM45EC is a next-generation German equatorial mount head built for astrophotographers and visual astronomers who need observatory-grade tracking performance in a field-ready form. Equipped with a high-resolution RA encoder that enables real-time periodic error correction (RPEC), the GEM45EC achieves sub-arcsecond tracking accuracy—a must-have feature for long focal length imaging and unguided exposure work.
This version includes only the mount head and a custom-fit hard carry case, making it ideal for users who already own a compatible tripod or pier. Whether you're assembling a highly mobile deep-sky rig or need a precision GoTo platform for semi-permanent installations, the GEM45EC offers impressive performance, intuitive operation, and rock-solid build quality in a compact footprint.
Sub-Arcsecond Precision, Field-Proven Design
At the heart of the GEM45EC is a high-resolution encoder installed on the right ascension axis, which allows the mount to correct tracking errors in real time without relying on user-trained PEC routines. The result? Consistent tracking accuracy of < 0.3 arcseconds RMS—ideal for astrophotographers working at long focal lengths or in remote setups where hands-free performance is essential.
Borrowing design principles from iOptron's Center-Balanced Equatorial Mounts (CEM series), the GEM45EC is re-engineered around a clean, compact CNC-machined body that offers an exceptional 2.53:1 payload-to-mount weight ratio. The mount head weighs just 17.5 pounds, yet supports a full 45-pound (20 kg) payload. That means you can easily carry an imaging train with a large refractor, off-axis guider, filter wheel, and camera—all on a mount you can pack and set up by yourself.
Smart Features That Matter
The integrated iPolar™ electronic polar scope makes polar alignment simple—even when Polaris is obscured. The system displays a real-time star field on your PC, guiding you to precision alignment without guesswork or manual offset charts.
Quick-lock gear clutches allow for fast balancing and setup, while the patent-pending Universal Self-Centering Saddle (USCS) accepts both Vixen and Losmandy-style dovetail plates. The internal cable management system includes USB and 12V DC pass-through ports, keeping your imaging cables organized and snag-free during tracking and slewing.
The Go2Nova 8407+ hand controller gives you access to a 212,000+ object database with intelligent GoTo, automatic zero search, park routines, and built-in GPS. And with a quiet precision stepper motor drive system and synchronous belt transmission, the GEM45EC offers smooth, silent operation ideal for both imaging and public outreach.
Performance and Construction Highlights:
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High-resolution encoder in RA axis enables < 0.3 arcsecond RMS tracking
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Real-Time Periodic Error Correction (RPEC)—no PEC training required
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17.5 lb mount head supports up to 45 lbs of payload
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Internal iPolar electronic polar scope included for fast, reliable alignment
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CNC-machined aluminum body, red/black anodized for durability
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Zero-backlash 216-tooth brass worm gears on both RA and DEC
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45mm steel shafts and 68mm axis bearings for rock-solid stability
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Dual dovetail saddle accommodates both Vixen and Losmandy plates
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ST-4 guiding port, USB, and 32-channel GPS module included
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Meridian flip, park/zero routines, and optional Wi-Fi (via iStarFi)
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Compatible with LiteRoc tripod, Tri-Pier, and custom piers
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Power draw: 0.6A (tracking), 0.9A (GoTo); 12VDC @ 5A input
Supplied Accessories – What’s Included
The GEM45EC (#7620ECA) mount head ships with everything you need for standalone deployment or integration into an existing mount setup. Inside the included custom-fit hard case, you’ll find the GEM45EC mount head, the Go2Nova 8407+ hand controller with coiled cables, GPS module, iPolar system, USB and RS232 communication cables, AC adapter (100–240V), and Quick Start Guide. This configuration does not include a tripod or counterweight, making it ideal for users who already own compatible accessories.
Observing Tip:
The GEM45EC’s encoder-based RPEC allows for long unguided exposures, making it an excellent choice for photographers who want to minimize guiding corrections or run multi-night automation scripts. Combine it with a motorized focuser and optional Wi-Fi module for a lightweight, remote-ready rig that doesn’t compromise on tracking quality.
Final Thoughts:
For astrophotographers looking for premium performance in a portable form, the iOptron GEM45EC mount head with hard case checks every box. It’s engineered with the stability and precision needed for deep-sky imaging, yet light enough to bring to a dark sky site. Whether you’re adding encoder precision to an existing setup or assembling a world-class travel rig, the GEM45EC delivers where it matters: accurate, reliable, and ready to track wherever the sky takes you.
