iOptron CEM40EC Center Balanced GoTo Equatorial Mount with 1.5" Tripod
Part Number: C404A1
Real-Time Precision Tracking in a Lightweight Field Mount
The iOptron CEM40EC represents a leap forward in portable equatorial mount performance. Building on the already-capable CEM40 platform, the EC version adds a high-resolution RA encoder and real-time periodic error correction (RPEC), delivering an exceptionally smooth tracking experience with <0.25 arcsecond RMS accuracy—no guiding required. For many imagers, that means longer subs, tighter stars, and fewer guiding headaches.
Despite its sophisticated tracking electronics and mechanical precision, the CEM40EC remains ultra-portable. The CNC-machined mount head weighs just 15.8 lbs, yet supports a full 40-pound payload with ease thanks to iOptron’s unique Center-Balanced Equatorial Mount (CEM) design. Whether you’re mounting a long refractor or a fully loaded astrograph, the CEM40EC handles it with stability and elegance.
This configuration includes iOptron’s 1.5" stainless steel tripod, a lightweight yet sturdy tripod ideal for visual observers and imagers using lighter optical tubes. The CEM40EC head also ships standard with a custom hard case, offering protection and portability for frequent travel or field deployment.
Center-Balanced Stability and Engineering That Travels Well
Unlike traditional German equatorial mounts, which offset the right ascension axis to one side of the tripod, iOptron’s patented center-balanced design places the mass of the payload directly over the support system. The result is a naturally more stable system with reduced flexure and torque—even when mounting heavier or asymmetrical equipment.
Internally, the CEM40EC features zero-backlash 216-tooth worm wheels, hardened steel Ø45mm axles, and large 68mm ball bearings on both RA and DEC axes. Combined with a 17mm worm gear and precision stepper motors, these components provide excellent tracking and slewing accuracy.
Where the standard CEM40 already delivers solid performance (±7 arcsec typical PE), the EC version takes it a step further. Its RA encoder monitors position in real time, dynamically correcting for tracking errors as they occur. This means no need for PEC training, no drift buildup, and highly accurate tracking even without an autoguider.
iPolar™ Built-In for Effortless Polar Alignment
The CEM40EC includes iOptron’s iPolar electronic polar scope as standard equipment. Factory-aligned and built into the RA axis, iPolar uses a sensitive imaging sensor and plate-solving algorithms to provide fast, dead-on polar alignment—even when Polaris isn’t visible.
Unlike traditional polar scopes that require careful sighting and visual access to the pole, iPolar works with obstructions in the way—making it perfect for suburban observing locations or obstructed views. Setup time is dramatically reduced, and GoTo performance improves noticeably as a result.
Full GoTo Control and Observatory-Class Electronics
Controlling the CEM40EC is iOptron’s Go2Nova® 8407+ hand controller, featuring a crisp, 8-line LCD screen, backlighting for night use, and a built-in heater to prevent fogging in cold conditions. The database contains over 359,000 celestial objects, including deep sky catalogs, named stars, solar system bodies, and user-defined targets. Star ID mode, pointing assistance, and custom tour features round out its capabilities.
The mount supports slewing up to 4.5°/second, allowing for quick transitions between targets, and includes ST-4 autoguiding, USB connectivity, and a 32-channel GPS for automatic time and location syncing. Wi-Fi control is available with an optional external adapter for those who prefer wireless tablet or PC operation using iOptron Commander or SkySafari.
The Universal Self-Centering Saddle (USCS) accommodates both Vixen-style and Losmandy-style dovetail bars, automatically aligning and clamping down securely without tools or adapters. And the integrated cable management system minimizes the risk of snagging during slewing, even with complex imaging setups.
Observing Tip
The CEM40EC’s real-time PEC means you can often image unguided for several minutes—a huge advantage for anyone doing mobile astrophotography or operating in areas with limited setup time. It’s especially helpful for wide-field imaging with fast refractors or short Newtonians, where guided accuracy might be more than you need, but tracking error still matters. Combined with the rapid iPolar alignment, this mount can take you from setup to first exposure in record time.
Final Thoughts
The CEM40EC with 1.5" tripod is a remarkable combination of engineering precision and lightweight practicality. With a high-resolution encoder providing sub-arcsecond tracking accuracy, iPolar for fast alignment, and a 40 lb capacity all in a mount head under 16 lbs, it’s a field-friendly powerhouse. This is a mount built for imagers who want observatory-class performance—without the observatory.
