Planewave .7 Meter Ritchey Chretien Automated Alt-Az Telescope

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  • Regular price $249,995.00

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Planewave .7 Meter Ritchey Chretien Automated Alt-Az Telescope

The PlaneWave Instruments PW700-RC is a 0.7 m (27.6 inch) f/6.5 Ritchey Chretien (RC) Automated Alt/Az Telescope System. The PW700-RC has fast Ritchey Chretien (or RC) optics made by PlaneWave, a dual carbon fiber truss design, with multiple cooling fans located near the front of the primary mirror to quickly cool the primary mirror and keep its temperature stabilized. The PlaneWave Instruments PW700-RC comes standard with a fork mount direct-drive alt/az mount with high level technology to set a new standard for research class observatory telescopes.

PlaneWave's PW700-RC Automated Alt/Az Telescope System has become the telescope of choice for universities, industry, and astrophotographers. PlaneWave offers the 0.7 m aperture PW700-RC with precision Ritchey Chretien optics to meet the custom and critical performance needs of the scientific community. This fully automated Alt/Az Telescope System is an observatory class instrument which will provide a dream research telescope system for a college or university observatory seeking an economical yet high performance optical system for teaching astronomy courses while also doing publishable astronomical research.

PlaneWave 0.7 m Ritchey Chretien Automated Alt/Az Telescope System Technical Features:

  • Ritchey Chretien Optical Design
  • Dual Nasmyth focus, allowing simultaneous mounting of two instruments or easy switching between visual and imaging applications
  • Direct-drive motors on each axis for smooth, fast, and virtually silent movement of the telescope
  • High resolution encoders on each axis for precise positioning
  • Zero backlash
  • Zero periodic error
  • PointXP mount modeling software
  • Field de-rotator / rotational field framing


In certain applications such as photometry and spectroscopy, refractive lenses could easily influence scientific data results by altering the spectral content of the acquired data. This could make it difficult to quantify the data. The PW700-RC as offered here in its native format (no field flattening lenses) uses only a primary, secondary, and tertiary mirror with reflective coatings. This can be useful when making scientific observations primarily on-axis as is the case in photometry and spectroscopy, and when wide field imaging is not a concern. Ritchey Chretien optics made by PlaneWave will provide excellent on-axis performance using only a hyperbolic primary and secondary mirror with no refractive optics in the light path. The tertiary mirror is a flat and thus has no power.

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. Besides, it is the way the big boys do it!

The carbon fiber truss design of the PW700-RC Ritchey Chretien (RC) Automated Alt/Az Telescope System telescope by PlaneWave will minimize problems of thermal expansion to prevent focus shift with changes in ambient temperature. Special dovetail expansion joints accommodate the difference in thermal expansion between carbon fiber and aluminum materials. The expansion joint allows the aluminum dovetail to expand and contract without stressing the carbon fiber lower truss.

Benefits of Nasmyth Focus: The Nasmyth Focus is along the altitude axis so there are virtually no balancing issue 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. Also, the provision of Nasmyth foci means it is easier to install large or bulky instruments for gathering data than it would be at a Cassegrain focus.

Rotating Tertiary Mirror: The PW700-RC 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 the optical beam from one port to the other in under 10 seconds.

Direct drive motors and encoders: Direct Drive motors mean that there are no gears to cause backlash and periodic error. With high-resolution 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 incredible speeds for tracking satellites or just to minimize target acquisition time.

The PlaneWave PW700-RC Ritchey Chretien Automated Alt/Az Telescope System has terrific specs for pointing and tracking performance, which is important for doing serious research with this scope. Pointing accuracy is 10 arcsecond RMS when using the PointXP Model, while the Tracking accuracy is 1 arcsecond error or better over a 3 minute track period.

For doing research in astronomy where reliable data is critical, incorporating a mount model program is highly desirable. PointXP5 provides the capability from within software to model your mount performance and its axis offsets, in this case for the Alt/Az mount. A good model will dramatically improve your mount’s performance. On a good mount with a good optical system such as the PlaneWave PW700-RC, PointXP5 can provide pointing performance with only a 5 arcsecond RMS error.

This Ritchey Chretien Automated Alt/Az Telescope System model PW700-RC by Planewave is the perfect choice of telescope for a college or university observatory seeking an economical yet high performance optical system for teaching astronomy courses while also doing publishable astronomical research work. It is also an ideal scope for the avid amateur astronomer who will be doing research such as photometry or spectroscopy, or astrometry over a narrow field of view. It will be great for visual astronomy too because of its high quality imagery for nearly on-axis objects.

This telescope weighs 1200 lb. not counting the shipping crate, and will ship truck freight. Call our Pro Services Department for information and lead times.


Aperture700 mm (27.5")
Back Focus309mm
Camera/Eyepiece ConnectionPlaneWave Bolt Pattern
Dawes Limit0.17 arcseconds
Drive TypeDirect Drive 3 Phase Axial Flux Torque Motor
Encoder Resolution0.08
Encoder Typestainless steel encoder tape
Focal Length4540 mm
Focal Ratiof/6.5
Glass TypeFused Sillica
Head DesignAltitude Azimuth
Highest Magnification1400x
Light Gathering Power10000x
Limiting Magnitude18
Optical DesignRitchey Chretien
Pointing Accuracy10 Arcseconds
Secondary Obstruction329mm
Tracking Accuracy1 Arcsecond or Less