iOptron GEM28EC German Equatorial GoTo Mount with iPolar, High-Precision Encoders, 1.5" Stainless Steel Tripod, and Hard Carrying Case
iOptron Part Number: G284A1
Precision doesn’t always come in a heavy package. The GEM28EC from iOptron is a testament to what modern CNC machining, encoder technology, and thoughtful engineering can do when combined in a compact German equatorial mount. With a payload capacity of 28 pounds but a head that weighs just 10 pounds, the GEM28EC offers a rare combination of portability, tracking accuracy, and advanced electronics, making it a standout performer for both visual observers and imaging enthusiasts alike.
If you’ve ever struggled with undersized mounts, vague clutches, or unpredictable tracking, the GEM28EC feels like a breath of fresh air. It’s built for those who want the performance of a permanent pier-mounted setup—but with the freedom to take it anywhere.
Engineered for Astrophotography Precision
At the heart of the GEM28EC is a high-resolution encoder system that drives periodic error to nearly negligible levels—under 0.3 arcseconds RMS. That puts it in a class of mounts costing significantly more. The inclusion of real-time PEC means it continuously corrects errors without needing a training session. You get repeatable performance across the entire imaging session, without having to rely solely on autoguiding to correct for mount flaws.
The dual-axis stepper motors use a synchronous belt transmission system connected to 144-tooth, 88mm drive gears on both axes, machined from brass. These mate with 35mm stainless steel RA and DEC shafts, giving the mount the torsional strength and long-term durability needed for extended exposures and repeated travel. And with a 0.17 arcsecond per step encoder resolution, even subtle tracking deviations are virtually eliminated.
This isn’t just a spec-sheet wonder. In the field, the GEM28EC delivers round stars, sharp nebulae, and clean galaxy arms—night after night.
A True Grab-and-Go GEM with Real Mount Stability
Despite its high precision, the GEM28EC mount head itself weighs only 4.5 kg (10 lbs), making it among the lightest EQ mounts in its class. Yet thanks to the encoder-assisted drive and premium machining, it offers a payload capacity of 12.7 kg (28 lbs)—a ratio of nearly 3:1. In real terms, that means you can mount a medium-sized refractor or imaging reflector without stressing the mechanics or losing tracking fidelity.
Included is a 10-pound counterweight, an 8” stainless steel counterweight shaft, and a 5” shaft extension, allowing you to balance a wide variety of telescope configurations without worrying about purchasing extras right out of the box.
The GEM28EC is a particularly strong match for those using apochromatic refractors in the 4" to 5" range, compact astrographs like the RASA 8 or HyperStar systems, and Newtonians up to about 6” or 8” depending on imaging train weight. Visually, it has no trouble carrying a larger SCT for deep-sky observation or planetary detail.
Clutches That Lock Firm—Controls That Feel Right
One of the more frustrating aspects of some portable mounts is their vague, weak clutch mechanisms. Not so here. The GEM28EC features large, spring-loaded quick-lock clutches on both axes. You get a positive, confident lock with minimal effort and no slipping, even in cold conditions or with gloved hands. Slewing the mount manually or switching between manual and motorized operation is a tactile pleasure, not a chore.
The gear system itself is spring-loaded, minimizing backlash and keeping the worm and wheel meshed properly over temperature swings and heavy loads.
GoTo Control, Your Way
The GEM28EC is powered by iOptron’s Go2Nova® 8409 controller, one of the most advanced GoTo systems in its class. It includes:
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An 8-line, 21-character LCD display—the largest of any hand controller on the market
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LED backlit keys for easy use at night
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Built-in heater so you can operate the system in conditions down to -20°C (-4°F)
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212,000+ object database, including:
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110 Messier objects
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Over 7,800 NGC entries
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Nearly 13,000 UGC galaxies
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Over 30,000 MCG objects
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195 named stars
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210 double stars
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38,000+ GCVS variables
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All 88 constellations
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116 asteroids, 15 comets, and more
Whether you’re tracking a planetary conjunction, chasing comets, or hopping through the Virgo Cluster, you’ll never run out of targets.
Built-In iPolar for Alignment Without Polaris
No view of Polaris? No problem. The GEM28EC includes iOptron’s iPolar electronic polar scope—a game-changing alignment tool built right into the RA axis. With iPolar, you can polar align in daylight, align from the southern hemisphere, or simply bypass the challenges of obstructed skies. It even helps beginners align with confidence, with a simple on-screen interface that provides feedback in real time.
For traditionalists or for fine-tuning, the mount also includes an altitude-azimuth adjustment system, complete with a large latitude setting scale (10° to 70° latitude range), built-in bubble level, and fine azimuth adjusters that give you ±6° of control.
Ready for the Modern Observer: WiFi, USB, and More
iOptron understands that modern astronomers use laptops, tablets, smartphones, and even Raspberry Pis to run their gear. The GEM28EC comes ready for all of it:
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Built-in WiFi for wireless control via apps and third-party software
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USB port for firmware updates and computer control (ASCOM/INDI compatible)
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RS232 port for legacy PC connections
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ST-4 guide port for standard autoguiding
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Strain relief clamp on the power cable to prevent accidental disconnections
The mount also supports an optional 32-channel GPS module, and the optional iGuider system (#3360) can be mounted directly for a tidy, integrated autoguiding solution.
The Right Tripod for the Job
Included with the GEM28EC is a 1.5" diameter stainless steel tripod with adjustable height. While lighter than 2” variants, the 1.5” tripod is more than capable of supporting the GEM28EC and its full-rated payload. It includes a cast metal spreader tray for increased stability and accessory storage and is light enough to make the entire rig easily transportable.
Tripod weight: 10.6 pounds (4.8 kg)
Total package weight (excluding counterweight): approximately 20.6 pounds
Mounting Compatibility
The GEM28EC uses a Vixen-style saddle, making it compatible with most modern OTA dovetail bars. If you use Losmandy-style plates, an optional dual saddle or adapter will be required.
Included Accessories
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GEM28EC Mount Head
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Go2Nova® 8409 Hand Controller
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1.5" Stainless Steel Tripod
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10 lb Counterweight
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8” Counterweight Shaft + 5” Extension
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AC Power Supply
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RS232 Cable
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Hard Carrying Case for Mount Head
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Integrated iPolar Polar Alignment Camera
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Built-in WiFi and USB connectivity
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Bubble Level, Latitude Scale, and Alt-Az Adjusters
Observing Tip
If you’re using a fast f/5 or shorter imaging scope, the ultra-low periodic error and tight encoder resolution of the GEM28EC make it an excellent unguided imaging platform—for exposures up to 2–3 minutes, depending on focal length. For longer exposures or narrowband work, add a lightweight guide scope and ST-4 autoguider for peak performance. With iPolar and PEC, polar alignment and tracking accuracy become fast, repeatable, and rock-solid.
The Bottom Line
The iOptron GEM28EC is an ideal mount for the astronomer who demands serious tracking accuracy, advanced electronics, and true portability. It’s not just an upgrade from an entry-level mount—it’s a long-term solution for field or backyard imaging and observing that won’t leave you wanting more. Whether you’re upgrading from a smaller rig or downsizing from a bulky setup, the GEM28EC will make you appreciate the quiet confidence that comes from precision engineering.
If your telescope deserves better tracking, your images deserve tighter stars, and your back deserves a break—this is the mount you’ve been waiting for.
