User's Manual

1. GEM28 Overview

The iOptron

GEM28 and GEM28EC mount is the next-generation compact German equatorial

mounts. Like their predecessors the GEM28 is designed with portability in mind, weighing in at only 10 lbs it

can support up to a 28lb payload an incredible 2.8 mount weight to payload ratio. We achieved this using

design methods developed to reduce mount mass in our CEM family of mounts. The German EQ versions

were created to satisfy consumer that prefer a more traditional mount and to function at higher latitudes.

Building on the legacy of earlier GEM models, such as iEQ30/45 mounts, we have added features

for convenience and functionality. A positive lock gear engagement system (easy to use even when wearing

gloves), Built-in Wi-Fi enabling unparallel connectivity and recordable permanent periodic error correction

(PPEC) to repeat optimal PEC training sessions (real time PEC on the GEM28EC). Regarding functionality

the GEM28 and GEM28EC delivers precise pointing and accurate tracking (PE <0.3 arcsec rms on the EC

model). The 212,000 object library ensures you’ll never run out of targets to see or image. The GEM28 and

GEM28EC set the new standard for compact equatorial mounts.

The mount has an integrated electronic polar finder scope known as the iPolar, or an AccuAlign

optical polar scope. The iPolar ensures the accurate alignment of a telescope, even when the pole star is

obscured.

The iOptron GEM28 mount uses the new Go2Nova® 8409 hand controller to navigate the night sky.

This incredible technology helps observers find celestial objects with the aid of the mount's 212,000+ object

database! For those looking for a telescope that has the capability of tracking and finding beautiful night sky

objects, this mount is a must have tool.

Features:

 German equatorial design, latitude range of 10° ~ 70°

 Ideal for both visual observation and astrophotography

 Low periodic error (< ± 10 arcsec for GEM28 and <0.3 arcsec for GEM28EC)

 Payload of 12.7 kg (28 lbs) with the mount-only weight of 4.5 kg (10 lbs)

 Spring loaded gear system

 Large easy to use quick-lock gear clutches

 Stepper motor with low power consumption

 Integrated iOptron iPolar

electronic polar scope or AccuAlign

dark field polar scope

 Polar alignment routine for those who can’t see the Pole Star

 Go2Nova

8409 controller with Advanced GOTONOVA

GOTO Technology

 Integrated ST-4 autoguiding port

 Built-in Wi-Fi

 USB port for firmware upgrade and computer control

 Standard 1.5 inch heavy-duty stainless steel tripod (5kg), optional LiteRoc

tripod (7.5kg)

 Die-cast metal tripod spreader with accessory tray

 Optional external 32-channel Global Positioning System (GPS)

 Optional hard carrying case (standard for EC model)

 Optional iGuider

autoguiding system #3360