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RC700 (f/12) Ritchey-Chrétien Observatory System

SKU# 700126Q

Price: $240,000.00


*Price is based on PlaneWave’s Pricing Policy

To fulfill the needs of demanding research, commercial, and defense applications, the RC700 features:

  • 0.7-meter f/12 (8,410mm focal length) Ritchey-Chrétien optical design.
  • Optimized central obstruction < 30 % for improved image contrast and optical fiber coupling efficiency.
  • Dual Nasmyth focus ports, each capable of holding over 300 lbs, paired with a PlaneWave Interface 4 (PWI4) software controllable tertiary mirror for fast changes between multiple instrumentation packages.
  • Direct-drive motors on each axis providing up to 50 degrees/second of smooth, fast, and virtually silent slewing of the telescope with zero backlash and zero periodic error.
  • On-axis 26-bit absolute encoders coupled to each axis for precise pointing and stable LEO satellite tracking.
  • Optional GPS/PTP encoder synchronization for precise time-stamping and carbon fiber hard-shroud for stray light mitigation.
  • Secondary mirror focusing for increased instrumentation backfocus distance.
  • Compatible with the Series-5 rotator for derotation.
  • Space-frame design with optional Coudé Path.
  • PointXP mount modeling software.
  • Picture is shown with:
    • Optional Piggyback DeltaRho 350 OTA and remote adjustable saddle sold separately*
    • Optional upper truss hard shroud


The RC700 is a complete observatory class telescope and direct-drive alt-azimuth mounting system, designed and engineered by PlaneWave. With a 70 mm image circle, the RC700 is designed to excel at imaging on large-format CCD cameras. The optical system utilizes a Nasmyth focus through both altitude bearings allowing your camera or eyepiece to remain at a fixed height while holding heavy instruments without needing to rebalance the optical tube assembly.

Instrumentation can be installed on both sides of the fork mount and easily accessed using the included rotating tertiary mirror system. With direct-drive motors, high-resolution encoders, and zero backlash or periodic error, the RC700 sets a new standard for 0.7-meter class telescopes meant for high-resolution imaging and free-space optical communication.

An alt/az mount is inherently more stable than an equatorial mount since there is no cantilevered mass, nor are there any large protruding counterweights to create a dangerous hazard in a public observatory. An alt/az telescope is also considerably more compact than its equatorial counterpart, allowing a larger telescope to fit in a smaller enclosure. The mass it takes to make a rigid alt/az mount is substantially less, leading to cost savings. Unlike German Equatorial mounts, there are no meridian flips to deal with. You can image from horizon to horizon continuously if desired. Alt/Az is more intuitive to use and no polar alignment is needed.

Benefits of Nasmyth Focus

The Nasmyth Focus is along the altitude axis, so there are virtually no balancing issues as you change out equipment. Eyepieces remain at a constant wheelchair-accessible height, greatly simplifying access to the telescope for public observatories. The rotating tertiary mirror allows you to switch from one Nasmyth port to the other in just seconds, allowing observers to easily transition between imaging and visual use.


Rotating Tertiary Mirror

The RC700 includes an integrated rotator for the tertiary mirror, with magnetic locks to position the mirror precisely for either Nasmyth focus position. The rotator can move from one port to the other in under 10 seconds. Tertiary Mirror Video


Direct drive motors and encoders

Direct Drive motors mean that there are no gears to cause backlash and periodic error. With 26-bit absolute encoders providing the feedback for the direct drive motors, not only will the telescope track without periodic error or have any backlash at all, but the mount will be able to counter against wind gusts. The direct drive motors can move the telescope at up to 50 degrees per second for tracking satellites, or just to minimize target acquisition time.




Optical System

Optical Design Ritchey-Chrétien
Aperture 700 mm (27.56 in.)
Focal Length 8,410 mm
Focal ratio f/12
Central Obstruction < 30 % of the Primary Mirror
Back Focus from Mounting Surface 12.62” (320.6mm)
Weight 2,500 lbs (1134 kg)
Optical Tube Dual truss structure with Nasmyth Focus
Dimensions 92.25″ H x 52″ W x 36″ D
Focus Position Nasmyth Focus

Mechanical Structure

Fork Assembly Space-frame for maximum stiffness
Optical Tube Dual truss structure with Nasmyth focus

Shown with optional upper truss hard shroud

Motion Control

Motor Control Industrial grade Elmo brushless motor control system and built in electronics
Azimuth Motor Direct drive 3 phase axial-flux torque motor
Altitude Motor Direct drive 3 phase axial-flux torque motor
Encoder – Azimuth and Altitude 255 mm stainless steel encoder ring with read-head yields 67.1 million counts per revolution of the telescope. This translates to about 0.019 arc-second resolution.
Motor Torque Approximately 170 ft-lbs continuous (Azimuth motor)
Drive Electronics Elmo Motion Control Systems drives
Telescope Control Software PlaneWave Interface 4 (PWI4) Software. Incorporates PointXP mount modeling software and All Sky PlateSolve, both by Dave Rowe. Also includes automatic focusing, dew heater control, primary mirror cover control, dome control and provides HTTP and ASCOM control interfaces. Linux and Windows compatible. MaxIm DL is required for camera control when building a pointing model within our PWI4 software.

System Performance

Pointing Accuracy (all-sky RMS) 10 arcsecond RMS with PointXP Model
Pointing Precision

2 arcseconds at sidereal velocity

Open Loop Tracking Accuracy

< 0.2 arcseconds over a 10-second period at sidereal velocity

Azimuth Range of Motion 660 degrees
Altitude Range of Motion 10- 90 degrees

Primary Mirror

Material Fused Silica

Secondary Mirror

Material Fused Silica

Tertiary Mirror

Material Fused Silica

NOTE: All specifications and dimensions are subject to change.  

For warranty information please check our Standard Warranty Page