PlaneWave 12.5-inch CDK f/8 Optical Tube Assembly

  • Telescope tube weight: 48.5-pounds, (with electronic focuser and dovetail).
  • Focal length: 2541 mm (100-inches).
  • Focal ratio: f/8.
  • Aperture: 318 mm (12.5-inch).
  • Image Circle: 52 mm.
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  • Regular price $8,500.00

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PlaneWave 12.5-inch CDK f/8 Optical Tube Assembly

CDK Design

The CDK is an innovative solution for unsurpassed astro-imaging quality and far exceeds the off-axis performance of most commercial telescope designs. It has no off-axis coma, no off-axis astigmatism, and a perfectly flat field 52 mm image circle, that will ensure perfectly round stars with sensors larger than 35 mm film (24x36  mm). This no-compromise design also is unique in making the optical alignment very forgiving and collimation super easy, by only adjusting the secondary mirror.

PlaneWave CDK12.5 Astrograph Meachanical Drawing with Ray Trace Lines

 Power/Controll Hub on the back face of the Planewave CDK12.5 Telescope

Pre-wired for Mirror Cooling & Dew Control

PlaneWave Telescopes are internally wired with cooling fans, heater pads, and a temperature sensor. The fans will quickly equilibrate the optics and are controlled via the optional Electronic Focus Accessory (EFA Kit). The optional Delta-T controller connects with the temperatures sensor and heater pads to make sure that the mirrors never reach the dew point throughout the night.

Superior Optics

Each mirror in a CDK is machine figured and hand-finished from Fused Silica, a synthetic amorphous glass that has a thermal expansion coefficient six times lower than Pyrex. It’s the primary choice for telescopes used in world-class observatories because of is consistent optical performance and unchanging shape when temperatures change.

Planwave Fused Silica Primary Mirror

Planewave CDK12.5 OTA Carbon Fiber Tube

Carbon Fiber Tube

Carbon fiber minimizes thermal expansion which causes an OTA's focus point to shift as the temperature changes. The closed tube protects the primary and secondary mirrors while also minimizing dew build up.

2.75-inch Hedrick Focuser

This heavy-duty no-slip focuser. The focus tube runs on 5 bearings and is driven by a lead-screw so there is no chance of slipping. It accepts an optional dial indicator and can be upgraded with PlaneWave's Electronics Focus Accessory (EFA Kit). The focus draw tube travel is 1.3-inches.

3D Rendering of 2.75-inch Hendrick Focuser Used on the PlaneWave CDK12.5

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Dovetail Expansion Joints

These joints allow for the difference in thermal expansion between the carbon fiber tube and the aluminum dovetail. The expansion joint allows the aluminum dovetail to expand and contract without stressing telescope.

What to order with the CDK12.5

All PlaneWave Telescopes are handled and shipped with the utmost care. When you order a telescope from PlaneWave, they make a custom shipping crate for the optical tube assembly. Because of this, it’s very important to consider getting the right accessories for this telescope at the time of purchase. Getting your accessories with the scope has a couple of other benefits than just the crating; one, it will help you save on additional shipping costs and two, all the accessories will be installed onto the telescope at the factory, making it usable right out of the crate.


Aperture318 mm (12.5")
Back Focus265mm
Camera/Eyepiece ConnectionPlaneWave Bolt Pattern
Corrected Image Circle52mm
Dawes Limit0.05 arcseconds
Focal Length2541 mm
Focal Ratiof/8
Glass TypeFused Silica
Highest Magnification636x
Light Gathering Power2064x
Limiting Magnitude16.3
Optical DesignCorrected Dall Kirkham
Secondary Obstruction118mm
Tube Diameter392mm
Tube Length890mm
Tube Weight48.5 lb


  • PlaneWave CDK 12.5-Inch Carbon Fiber Tube OTA.
  • Dovetail Expansion Joint.
  • 2.75-inch Hedrick Focuser.
  • Cooling Fans.


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Cecil C.
United States United States
Very High Quality

Very impressed so far. Excellent image quality across the field. Great mechanical quality.