iOptron CEM120EC Center-Balanced Equatorial GoTo Mount (Mount Head Only)

iOptron CEM120EC Center-Balanced Equatorial GoTo Mount (Mount Head Only)

iOptron CEM120EC Center-Balanced Equatorial GoTo Mount (Mount Head Only)

B&H # IO7301 MFR # 7301

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Expected availability: 3-5 weeks

Product Highlights

  • Motorized and Computer-Guided EQ Mount
  • Center-Mounted Design, 115-pound Payload
  • Go2Nova 8407 v2 Hand Controller
  • Real-Time Periodic Error Correction
  • Very Low <0.15 Arcsec Periodic Error
  • Multiple Tracking and Slew Speeds
  • Built-in 32-Channel GPS Receiver
  • Built-In WiFi and LAN for Remote Control
  • 17" Losmandy-Style Saddle
  • Mount Head Only - Tripod/Pier Required
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Options: Real-Time PEC, <0.15 Arcsec Error

Permanent PEC, <+/-3.5 Arcsec Error

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Real-Time PEC, <0.15 Arcsec Error
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iOptron CEM120EC overview

  • 1Description

The CEM120EC Center-Balanced Equatorial GoTo Mount from iOptron features an innovative weight-distribution design coupled with precise extended tracking capabilities to create a mount ideally suited for long-exposure astrophotography and observation. Its center-balanced design puts the weight of the optical tube assembly (OTA) and accessories directly over the mount's center of gravity, which gives it better stability and a greater payload capacity over other mounts. Additionally, the counterbalance shaft length is adjustable to keep it from interfering with whatever pier or tripod is being used.

This upgraded model of the CEM120 is engineered with highly precise encoders to bring its tracking error down to less than 0.15 arcsec, with a Real-Time Periodic Error Correction (RPEC) system that constantly monitors the accuracy and automatically correct errors to improve tracking and GoTo accuracy. In addition to improving astrophotography/imaging results, the extended tracking accuracy makes long-term observation of specific objects or areas of interest easier.

Included with the mount is the Go2Nova 8407v2 controller. This handheld computer guider has a database of over 350,000 objects and is flash updatable from the iOptron website with firmware updates that increase its accuracy and add celestial objects. The database includes the planets, galaxies, star clusters, quasars, and nebulae as well as seven astronomical catalogs including Messier and NGC IC. It also has stars, comets, asteroids, and constellations, and can store user-defined objects to easily find and go to favorites. The mount has nine slew speeds up to 4°/second and can be manually controlled for quick observations. Adding to its ease of use, iOptron outfitted the mount with a 32-channel GPS receiver that sends highly accurate location coordinates, date, and time information automatically to the hand controller for more precise setup. The CEM120EC also comes with built-in WiFi and LAN interfaces to make wireless or wired remote control fast and easy.

  • Motorized and computer-guided equatorial mount
  • Innovative design puts the payload weight on the mount's center of gravity for greater stability and better counter-balancing
  • 115 lb payload capacity, excluding counterweight
  • Large spring-loaded 17.2" Losmandy saddle is designed to carry large and heavy OTAs
  • Track objects below the horizon line when observing from an elevated position
  • Declination shaft doesn't obstruct optional alignment scope when installed for faster and easier polar alignment
  • Manual clutches on both right ascension (RA) and declination (dec) axes for fast and easy movement by hand
  • Integrated 32-channel GPS receiver communicates information to the Go2Nova controller
  • Built-in WiFi and LAN antennae for wireless or wired remote operation
  • ST-4 autoguiding port to interface with optional autoguiding computer software for improved long-duration tracking
  • Automatic meridian flip allows for better long-duration tracking
  • Advanced cable management system has multiple identical-use ports to reduce cable wrap and limit obstruction
  • 22 lb counterweight and stainless steel shaft included
  • 9.1 x 8.3" (23 x 21cm) mount base size
  • Mount only; tripod or pier required for proper use
Motors and Gears
  • Real-Time Periodic Error Correction system constantly automatically identifies and corrects tracking errors to constantly improve accuracy over time; <0.15 arcsec tracking error
  • Precise 128 micro-step stepper motors allow accurate tracking without vibration
  • 0.07 arcsec motor resolution
  • Highly precise 0.035 arcsec encoder resolution greatly improves GoTo tracking and PEC correction
  • 216mm, 360 teeth, zero backlash RA and dec worm wheels
  • 80mm, steel RA and dec axles
  • 125mm RA and dec bearings
  • 110-240 VAC power adapter included; consumption: 0.7A tracking only, 1.8A using GoTo
Go2Nova 8407 v2 Hand Controller
  • User-friendly menu-driven interface
  • 350,000+ object database includes planets, stars, constellations, and seven complete astronomical catalogs
  • Multiple tracking rates including lunar, solar, sidereal, and King's; programmable custom user-defined speed
  • Nine selectable slew speeds: 1x, 2x, 8x, 16x, 64x, 128x, 256x, 512x, 4°/sec (max)
  • Multiple alignment assistance methods: Solar System Align, One-Star Alignment, Two-Star Alignment, Three-Star Alignment, Polar Iterate Align
  • Pole Star Position function displays the position of Polaris (Northern) or Sigma Octantis (Southern)
  • Enter specific RA and dec coordinates of objects for immediate GoTo
  • Identify function allows user to center a star and the database will match it to a known star
  • Programmable anti-backlash adjustment for smoother tracking
  • Updatable firmware through built-in serial port
  • 8-line, 21-character/line, red-light backlit LCD screen
  • Integrated red reading/task light on back
  • Built-in heater for larger operating temperature range
  • Powered by mount for ease of use and to reduce weight

Database Details:

  • Solar system: 9 objects including Moon, Sun, planets
  • 92 popular deep-sky objects with their common names
  • Messier Catalog: Consists of all 110 Messier objects
  • NGC Catalog: Consists of 7840 objects
  • IC Catalog: Consists of 5386 objects
  • PGC Catalog: Consists of 73,197 objects
  • Caldwell Catalog: Consists of 109 objects
  • Abell Catalog: Consists of 4076 objects
  • Herschel Catalog: Consists of 400 objects
  • 259 stars with their common names
  • 208 double/multi stars
  • HIP catalog consists of 120,404 records
  • 15 comets
  • 116 asteroids
  • 88 modern constellations
  • Up to 73 user-defined comets, and/or up to 64 stars


In the Box
iOptron CEM120EC Center-Balanced Equatorial GoTo Mount (Mount Head Only)
  • RS232 to RJ9 Serial Cable
  • Go2Nova 8407 v2 Hand Controller
  • 22 lb Counterweight
  • Stainless Steel Counterweight Shaft
  • 12V/5A AC/DC adapter
  • Hand Controller Cable
  • GPS External Antenna
  • WiFi External Antenna
  • 4 x Base mounting screws
  • Limited Two-Year Warranty
  • Table of Contents
    • 1Description

    iOptron CEM120EC specs

    Mount Type Equatorial
    Load Capacity 115 lb / 52 kg, excluding counterweight
    Mount 17.2" Losmandy saddle
    Motor Precision 128 micro-step stepper motor
    Resolution: 0.07 arcsec
    Right Ascension Worm Wheel 8.5" / 216mm, diameter
    360 teeth
    Zero backlash
    Right Ascension Axle 3.1" / 80 mm, steel
    Declination Worm Wheel 8.5" / 216mm, diameter
    360 teeth
    Zero backlash
    Declination Axle 3.1" / 80 mm, steel
    GPS Internal 32-channel GPS receiver
    GoTo Capability Go2Nova 8407 v2 hand controller
    Altitude / Latitude Adjustment Altitude: ±5°, 3 arcmin division
    Latitude: 0 to 68°, 0.5 arcmin division
    Polar Axis Scope Optional
    Includes Tripod/Pier No
    Counterweight 22 lb / 10 kg
    Ports 2x 12VDC, 1A
    1 x 5VDC, 1A
    2 x DC, 5A
    1 x ST4
    1 x 6P6C
    4 x USB 2.0
    1 x USB 3.0, powered
    1 x USB for PS
    1 x AUX
    Power Requirement 12VDC, 5A
    Operational Temperature 14 to 104°F / -10 to 40°C
    Mount Size Not specified by manufacturer
    Weight 57.0 lb / 26.0 kg

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