iOptron GEM45 German Equatorial GoTo Mount

iOptron GEM45 German Equatorial GoTo Mount

  (2 Reviews)
✓ 2 year warranty


1x in stock shipped 1-2 working days

About this product

Model:  iop_gem45_7603a-hc_1.75
Part Number:  7603A-HC

The GEM45 is the first of iOptron's next generation German equatorial mounts. 

Using experience gained during the development of their CEM series, iOptron have removed unnecessary weight resulting in a portable 7.2 kg / 15.8 lb mount with an impressive 2.8 payload-to-mount weight ratio. 

With its integrated electronic polar scope (iPolar) polar alignment is a breeze, even when the pole star is obscured.

IOptron's reliable ultra-quiet stepper motors provide precise pointing and tracking together with low power consumption. Large levers make it easy to engage the drive gears into place, even when wearing gloves. 

Integrated internal cable management means there is little chance of your cables becoming snagged and a new, patent pending, Universal Self-Centering Saddle (USCS) accommodates both Losmandy and Vixen style dovetail plates. 

A new 'LiteRoc' 1.75" tripod delivers high stability in a lighter, more compact package.

Other features include computerised GOTO with a 212,000+ object library (includes star identification) GPS and Wi-Fi (requires optional iStarFi adapter).


  • Next generation German Equatorial Mount
  • Suitable for both visual observation and astrophotography
  • Maximum payload of 45 lbs (20 kg) with a mount weight of only 15.8 lbs (7.2 kg)
  • Easy to use quick-lock gear clutches
  • Integrated iPolar electronic polar finder
  • Low periodic error (< ± 7 arc seconds)
  • Permanent periodic error correction (PPEC)
  • Ultra-quiet precision stepper motors for precise GOTO and accurate tracking
  • Go2Nova® 8407+ controller with Advanced GOTONOVA® GOTO Technology and built-in heater
  • Integrated ST-4 autoguiding port
  • 32-channel Global Positioning System (GPS)
  • USB communication port
  • Integrated cable management system
  • New, patent-pending iOptron universal saddle
  • All metal, CNC machined body with red/black anodised surfaces
  • Optional WiFi for mount control via SmartPhone/Tablet/Computer
  • All new LiteRoc 1.75" tripod with improved stability and leg locks

Go2Nova Hand Controller 8407

  • 200,000+ object database
  • 8 line, 21 character back lit large screen LCD
  • Low temperature operation as low as -20ºC
  • User friendly interface
  • 9 speed slew control with quiet mode
  • Large object database
  • Serial port for firmware upgrade

What's in the box

Supplied in two boxes. 

  • GEM45 mount head
  • CW shaft
  • 1x 5kg / 11lb Counterweight, when purchased with a tripod.
  • GO2Nova 8407+ hand controller with cord. 
  • GPS Module
  • RJ11 Cable x2
  • RS232-RJ9 Cable
  • USB Cable
  • Alignment Peg
  • 1.75" tripod and accessory Tray
  • Optional Hard Case


Mount German Equatorial Mount
Max payload* 45 lbs (20 kg), exclude counterweight
Mount weight 15.8 lb (7.2 kg)
Payload/Mount weight 2.78
Structure Material All metal, CNC machined
Exterior Finish Anodised red/black
Latitude adjustment range 14º ~ 68º
Azimuth adjustment range ± 6º
Tracking accuracy (PE)** <±7 arcsec
Period 400 sec
Worm diameter Φ17mm, Brass
Right Ascension worm wheel Φ110mm, 216 teeth, zero backlash
Declination worm wheel Φ110mm, 216 teeth, zero backlash
Right Ascension axis shaft Φ45mm steel
Declination axis shaft Φ45mm steel
Right Ascension bearings Φ68mm
Declination bearings Φ68mm
Counterweight shaft Φ28X280 mm, Stainless Steel (1.2 kg)
Counterweight 11lbs (5kg) x1 (when purchased with a tripod)
Motor Precision stepper motor, 1.8º/128X micro-step
Motor resolution 0.08 arcsec (200 PPS)
Transmission Synchronous belt
Hand Controller Go2Nova® 8407+, 8 line 21 character LCD
Star Database 212,000+, star identification
Power DC 12V, 5A
AC adapter 100V ~ 240V (included)
Power consumption 0.6A(Tracking), 0.9A(GOTO)
Power-down memory Yes
Polar scope Internal iPolar TM electronic polar scope
Meridian treatment Stop (0-20° pass), flip
Zero position Automatic zero search
Dovetail saddle iOptron Universal Saddle, 5"
Max slew speed 4.5°/sec (1080X)
Guiding port ST-4
Communication port USB
WiFi External (optional)
Cable Management DC12V (3A), ST4,USB
Tripod 1.75" Stainless Steel(~8kg), or optional Tri-pier
Hard case Optional
Operation temperature -10ºC ~ 40ºC
Warranty Two year limited

* OTA size and length dependent
** Measured with encoder, 400 seconds

Downloads / Manuals


iOptron GEM45 Quick Start Manual


Coming soon

iOptron Telescope ASCOM Driver:

Coming soon

Customer reviews

Average Rating (2 Reviews):  
Write a Review and share your opinions!

Rating (max 5):  
Very quick to set up
16 January 2021  | 

I've used this mount since September 2019, first with an EdgeHD800 and then with a WO GT81 and the feature that stands out most is how quick and easy it is to set up. This is mostly due to the light weight of the mount and tripod, which makes it possible to carry it outside fully assembled with the OTA. Then the built-in iPolar makes for very quick and accurate polar alignment - once calibrated to the mount, you only have to adjust the Alt and Az knobs to put the circle on the cross to give very accurate alignment in seconds. I have tried the Polemaster, Sharpcap and others, but none of these come close IMHO. Also, the GPS unit ensures that your time and location are accurately set. The through the mount wiring is very convenient to avoid tangles for USB and 12v, although sadly 1Amp capacity is insufficient to run dewbands and a camera cooler. Once you have called up the zero position from the hand control and run a plate solve to sync the mount to the sky, you can accurately centre any object you want, provided it's above the horizon!

Rating (max 5):  
Very nice mount
01 October 2020  | 

I purchased this mount in May and have been using it with a Vixen VMC200L and an Altair Wave 102 ED plus A/G and camera. Max pay load I have used is around 10kg. I have used the mount with mains power only so I have no idea how heavy the power consumption is in reality. Overall I'm very happy with it and it is undoubtedly a step-up from the Celestron CG5 AT I was using previously.

My views of pros & cons are:
1. iPolar alignment is so much easier than grubbing around on the floor trying to squint through a polar alignment scope.
2. Guiding performance has been very good.
3. It is relatively lightweight for the payload and easy to assemble. A slot of the allen key is a nice touch.
4. I bought the carry case and that is a nice touch.
5. The ioptron hand controller is good to use - clear and the menus are well laid out, IMHO.
6. The USB port which feeds though to a USB port just below the clamp is really useful. Likewise the 12V auxiliary socket.
7. It is visually attractive and well finished.

1. The allen key bolts for the mount head to the tripod are a little fiddly in the dark (but do hold the mount well).
2. The clamp screws are a bit on the small side I think. They have allen-key sockets so I use an allen key to tighten the dovetail into the clamp. It usually takes a couple of goes to get them tight.
3. The rubber feet on the end of the tripod legs come off and get lost. Aside from the feet, I've had no problems with the 1.75" tripod (although I am no where near the payload limit).
4. 5kg counterweight is too light.

A suggestion for improvement would be to have an internal USB hub inside the mount head and then to have, say, three USB ports to connecting A/G, camera etc.


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