With a head design and precise synchronous belt transmission that improve tracking accuracy with reduced vibration, the iOptron GEM28 GoTo EQ Mount makes an ideal mount for your astronomy and astrophotography needs when using small to medium refractors, reflectors, or Cassegrain optical tubes. Its combination of a powerful computer hand controller, traditional AccuAlign polar alignment scope, and integrated Wi-Fi module will enable you to spend less time aligning your mount and more time enjoying the wonders of the universe. This version of the GEM28 comes with an upgraded tripod to their LiteRoc model that offers the solid support of a 2" tripod with the portability of a smaller one for off-the-grid observation sessions and a hard carrying case to safely store and transport the mount head and accessories.

Motorized Computer-Controlled EQ Mount    Go2Nova 8409 Computer Controller    212,000-Object Database    Multiple Assisted Alignment Procedures    Permanent Periodic Error Correction    Built-In Wi-Fi Module    Integrated AccuAlign Polar Scope    Vixen-Style Dovetail Saddle    Hard Case for Mount & Accessories    Adjustable-Height LiteRoc Tripod

• Ideal for small to medium sized refractors, reflectors, and Cassegrain optical tubes
• German equatorial configuration provides smooth and accurate single-axis celestial tracking for observation and astrophotography
• <±10 arcsec of periodic error that can be trained out over time with PPEC function on hand controller
• 28-pound payload capacity, excluding included counterweight
• 10-70° latitude; ±6° azimuth adjustment range
• Built-in Wi-Fi module allows you to control the mount via smartphones running controller app
• 3.8" Vixen-style dovetail saddle
• Retractable counterweight bar prevents hitting the tripod or otherwise interfering with the mount's movement; 10-pound counterweight included

• Synchronous belt transmission improves tracking accuracy, with reduced vibration, especially with heavy loads
• Less than ±10 arcsec periodic tracking error
• 1.8° stepper motor with 128x microdivision
• 88mm, 144-tooth right ascension (RA) and declination (dec) aluminum worm wheels with zero backlash
• 55mm RA and declination ball bearings provide smooth movement with minimal vibration
• 35mm steel RA and dec axis shafts
• RA and declination gear switches release the gears for balancing OTA
• 0.17 arcsec motor resolution
• Low power consumption: 0.6A (tracking), 0.9A (using GoTo)
• Runs on included 12 VDC, 5A power adapter; plugs into a standard 110-240 VAC North American outlet

• 212,000-object database includes the moon, sun, planets, stars, comets, asteroids, and constellations
• Multiple assisted alignment procedures use the iPolar electronic polar finder
• Slew speeds: 1x, 2x, 8x, 16x, 64x, 128x, 256x, 512x, MAX (6°/sec)
• Permanent periodic error correction (PEC) eliminates tracking errors for long-exposure astrophotography
• Automatic tracking rate based on the selected object being tracked
• ASCOM-compatible computer control with planetarium software via integrated ST-4 autoguiding port
• Serial port for firmware upgrade
• Adjustable key and display brightness
• 8-line/21-character LCD screen; backlit 19-button user interface

• Factory installed in the altitude axis of the mount
• Helps you quickly and accurately equatorially align your mount without the need to connect it to a laptop
• Two sets of three concentric circles are clearly marked for aligning the mount on Polaris in the northern hemisphere or Sigma Octantis in the southern

• Safely carry, transport, and store mount head, hand controller, and counterweight shaft
• Aluminum case with reinforced corners
• Dual latches
• Molded hinged handle
• Foam-lined lid and custom-cut foam insert prevent items from shifting

• Innovative design provides the stability of a large 2" tripod, but with lighter 1.75" diameter legs
• Specially designed leg cuffs and sockets and locking levers add rigidity with less wobble when legs are fully extended
• Spreader locks legs into position to add stability and vibration suppression
• Minimum height: 30" (76.5 cm)
• Maximum height: 47" (116.8 cm)
• Weight: 15 pounds

Related Questions and Answers

Q: 1. Does this come with the cloth carrying case, as I have seen on the iOptron website?

A: There a carrying case but it isn't cloth; it's more like a synthetic mete rial.

Q: 2. I am in Ecuador, just 200 miles south of the equator. Will this work at a latitude of almost 0?

A: Short answer is yes. But the polar scope will be of no use since both the north and south poles will not be visible. Your polar axis will be essentially horizontal. You will need to line up this axis so it points south. There will be a lot of torque on this axis from your camera load, so keep it simple! I'd suggest contacting the manufacturer for advice.

Q: 3. Does the iOptron SkyTracker Pro rotate 360 degrees?

A: Yes...take 24 hours to rotate 360 degrees. Never needed to use it for more than about 4 hours though. Great addition to my night sky imaging kit.

Q: 4. Can this be used to photograph deep space objects like the Orion nebula? I am planning to use my tamron 150-600 on a Sony A7R2. Would it work with this combo?

A: Yes however I would recommend getting the Ball Head, and Counter Weight with that set up. So it can support that weight.

Q: 5. Hello. How well does the rechargeable battery perform in cold weather? best skies are often in the dead of winter. Thanks in advance.

A: I've used it in the cold mountain-top but have not run the battery down, most I've seen is about 4 hours use with battery still doing well. I do take a USB battery tank along as a backup.

Q: 6. Can I solar align in the daytime to photograph the eclipse ?

A: Exposures will be so relatively short accurate polar alignment will not be necessary. Simply point the mount to magnetic north and that will be more than sufficient; especially since the camera lens focal length will be under 500mm, I assume.

Q: 7. Does this tracker have a setting that will just rotate horizontally without tilting?

A: There is no setting , but it is a matter of set-up. Mount the SkyTracker with the camera mounting block level in all directions. The mounted camera will then rotate continuously, and very slowly, across the horizon.

Q: 8. How is the Skytracker programmed or set to track the sky based on location, season and time?

A: You simply use the included polar scope to do a polar alignment. Once it is polar aligned it will automatically rotate at the speed set with the selector switch whenever the power switch is turned on. This will give a rough polar alignment and ok tracking accuracy.For better tracking accuracy there are Apps available which allow you to enter your precise location and will then show precisely where in the polar scope reticle to align the pole star. This will give you the best accuracy possible with this unit.

Q: 9. Can you add gps to this setup?

A: Yes, iOptron GPS Module for CEM26, CEM40, GEM28, GEM45 Mounts BH #IO8438 • MFR #8438 https://www.bhphotovideo.com/c/product/1625961-REG/ioptron_8438_gps_module_for_cem26.html

Q: 10. Accepts cameras weighing up to 3 kg (6.6 lbs) Is the weight of the ball head and optional counter weight kit included in the weight limit?

A: That is the mount alone without the Ball Head, and Counter Weight added.