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iOptron GEM45 Mount Head in Hard Case

SKU : IO-7620A-HC

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  • A German Equatorial Mount
  • Includes a fitted Hard Case
  • For both Visual Observations and Astroimaging
  • Easy Quick-lock Gear Clutches
  • Integrated iPolar Electronic Polar Finder
  • Low PEC, uses PPEC
  • Precision Stepper Motor
  • 32-Channel GPS


Product Details

  • The Innovative ideas applied to a time tested design make the iOptron GEM45 next-generation German equatorial mounts exactly what you need.

    This sharp looking CNC body tells you the GEM45 is a top-quality mount in both form and function. While utilizing their experiences gained during the development of this CEM series, iOptron designers were able to remove unnecessary bulk giving the GEM45 an incredible 2.8 payload to mount weight ratio. This compact 15.8-pound mount can precisely GOTO an object and track with up to 45-pounds of gear onboard. With its integrated electronic polar scope (iPolar), polar alignment is a snap, even when the pole star is obscured. Large levers on the quick-lock drive engagement system make it easy to snap its drive gears into place even when wearing gloves. There is little chance of your cables getting snagged with the GEM45's internal advanced cable management system. A new, patent-pending Universal Self-Centering Saddle (USCS) accommodates Losmandy and Vixen-style dovetail plates. The GEM45 mounts utilize reliable stepper motor drive systems with iOptron's low power consumption technology.

    A 212,000+ object library with star identification, GPS, Wi-Fi (requires optional iStarFi adapter) are a few of the desirable features standard on a GEM45 mount.

    iPolar is included.

    Major Features:

    • German equatorial mount with innovative features
    • Idea for both visual observation and astrophotography
    • Maximum payload of 45-pounds (20 kg) with the mount weight of only 15.8-pounds (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)
    • Precision stepper motor 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
    • Cable management system
    • New, patent-pending iOptron universal saddle
    • All metal, CNC machined with red/black anodized


    Tripod and counterweight are not included.

    Their optional new LiteRoc 1.75-inch tripod delivers rock solid stability in a lighter, more compact package.

  • specifications

    Free ShippingYes
    Head DesignEquatorial
    Instrument Capacity45 lb
    Mount Head Weight15.8lb
    Telescope ConnectionDual Vixen & Losmandy
    Tracking Accuracy<±7 arcsec
    Warranty2 Year Limited Warranty
  • included items

    • iOptron GEM45 mount (#7620A, with black gear switches)
    • Go2Nova 8407 Hand Controller
    • Stainless steel counterweight shaft
    • Internal iPolar electronic polar scope
    • GEM45 GPS module
    • AC adapter (100V-240V)
    • 2x coiled control Cable (6P6C RJ11 to RJ11, straight wired)
    • Serial cable (RS232 to RJ9)
    • USB cable
    • Hard case
    • Quick Start Guide

    Technical Specifications:

    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 Anodized 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 Not included
    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
    GPS Yes
    WiFi External (optional)
    Cable Management DC12V (3A), ST4,USB
    Tripod Not included
    Hard case Yes
    Operation temperature -10ºC ~ 40ºC
    Warranty Two year limited

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

Product Reviews

Customer Reviews
4.0 Based on 3 Reviews
5 ★
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Scott P.
United States

Setting the GEM45 up

Setup went well but there should be a LARGE caution with respect to the allen wrench that is provided and is in the mount. The allen wrench goes through the RA shaft so if it is not removed when trying to slew the mount, it prevents the shaft from turning. It made a loud noise and once I realized what was going on, I removed the allen wrench and it seems to be OK. Hopefully it didn't damage anything. Not a brilliant idea to put the allen wrench in a place where it can damage the gears. There is very little guidance on what all the USB connections are for. I connected an ASIAIR Plus to the USB A connections on the plate the telescope is mounted to but that did not work. When I plugged it into the USB Type B connection on the back by the power switch it worked. I have not had a chance to try it under the stars yet but it seems to checkout in the house so far.

Stu P.
New Zealand New Zealand

Good mount

I purchased the mount head for a wide field imaging rig.I combined this with a WO Redcat and ASI2600MC and also a TPO UltraWide 180 f/4.5 Astrophotography Lens. I also added a ASIair pro for a simple portable rig. I received the mount and had it in storage for a few months due to weather and work.I got it out in the end and put it together.I didn't know that I wouldn't get a mount cable to update the firmware.I also didn't get the weights with the mount but I did know this. I did get the 1.75-Inch LiteRoc Tripod with it but the mount head did not fit so I had to contact ioptron and got the one that did. At last I managed to get some testing done and found that the guiding was terrible. I spent some time looking into it and at one stage I was going to send the mount back to OPT but after some careful digging I changed the guide settings in PHD which made the difference and in the end I was able to get very good guiding and when turning on PEC I can get an error of around .40 to .70 depending on the night.I have attached a PHD screenshot. The Ipolar worked well and was easy to use.I don’t much care for the software but overall no issues and on a good night with a wide field setup you can easily get a 5min exposure unguided. The go-to works ok but it has a tendency when you do a 1 or 2-star alignment to go miles away from the alignment star even though you have good polar alignment.I haven’t figured that out yet but I am hoping that a firmware upgrade will fix this(I had to order the cable from ioptron)This can cause the alignment to fail.But most of the time its ok.After a 2 star alignment most objects are somewhere in the field of view.However when using the ASIair the alignment is perfect right on centre every time. Due to a software bug that has not been fixed by ZWO or ioptron (at the time of writing this review )the mount normally fails to connect to the ASIair.After spending around 20 hours of trouble shooting I still haven’t corrected the issue.This is the main reason for giving this mount 4 stars. Currently I have not tried a heavy telescope but plan to try a C11 so that will be interesting to see how that goes. Attached are a couple of 1X15min exposures taken with the ASI2600MC no calibration files and only stretched a bit not much else done.These were just to test the guiding. But overall it is well made and doing adjustments for polar alignment is o.k. If you want a pretty portable and easy-to-use mount this might be the way to go.But until software bugs are fixed I cannot recommend the ASIair pro to work in conjunction with the mount.

OPT Telescopes iOptron GEM45 Mount Head in Hard Case ReviewOPT Telescopes iOptron GEM45 Mount Head in Hard Case ReviewOPT Telescopes iOptron GEM45 Mount Head in Hard Case Review
anthony s.
United States United States

Impressive mount for the money!

Mount appears to be very well made. Hand-controller firmware required update to be useable. It did not even recognize the mount as shipped. Luckily, the documentation for the update process is decent (serial port is required). iPolar is awesome after figuring out the alignment procedure (starting position is slightly ambiguous in the documentation). The unit I received seems to be an updated model. The main power input is 2.5mm x 5.5mm, which means the more common 2.1mm x 5.5mm won’t work (there are very inexpensive adapters available). I bough an iOptron’s DC car charger cable separately thinking that would work, but it came with 2.1mm x 5.5mm, so they haven’t quite worked out a variant for the new version of the GEM45. The AC power supply shipped with the unit works, though. Also on the new model, the dual *****/Losmandy saddle has been improved and no longer requires flipping over blocks to switch from one style to the other. The new system worked great for both Losmandy and ***** dovetails and once secured, I had no slippage at all. I did have to remove, clean and lubricate the thumbscrews for the saddle, though. As shipped, they had residual metal dust in the tapped holes and when tightening the thumbscrews, you could feel a terrible grinding on the threads. After removing the thumbscrews and spring-loaded pinch blocks, I blew out the tapped holes with compressed air and a lot of debris came out. I applied a light grease to the threads after cleaning and then all was good. First light, mount performed great. Polar alignment stayed “green” for hours, and after a 1-star alignment, slews seemed right on. 2-minute, unguided exposures yielded round stars with 100mm f/9 apo. My setup balanced nicely with an 11 pound counterweight, but the weight was close to the end on the shaft. Heavier setups (over 20 lbs) will probably require more counterweight. If it weren’t for the work required to get the saddle cleaned up and hand controller firmware updated to work at all, I would definitely give 5 stars.

OPT Telescopes iOptron GEM45 Mount Head in Hard Case Review