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Planewave CDK12.5 Optical Tube Assembly

SKU 125104Q
Original price $12,000.00 - Original price $12,000.00
Original price
$12,000.00 - $12,000.00
Current price $12,000.00


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The CDK12.5 is an innovative telescope for unsurpassed astroimaging, research, or satellite tracking.

  • f/8 and 2541mm focal length.
  • No coma, no off-axis astigmatism, and no field curvature.
  • Pinpoint stars across a 52mm image circle.
  • Rock solid fused silica mirrors with low thermal expansion.
  • Carbon fiber optical tube assembly for rigidity and fast cooling.
  • Simple secondary mirror collimation thanks to the fixed primary mirror.

Capturing the most stunning astrophotographs possible is something our team is passionate about. From design to manufacture, our goal with the Corrected Dall-Kirkham (CDK) 12.5" telescope was centered around performance and ease of use. The CDK12.5 is an incredible breakthrough in telescope technology and produces no off-axis coma and no off-axis astigmatism. Additionally, the CDK12.5 provides a perfectly flat field so your astrophotographs will have stunning clarity from corner to corner of the image without field curvature degrading the photos. Offering the simplicity of single-mirror collimation, the stray light control of advanced baffles, structural performance created through finite element analysis (FEA), and decades of telescope design experience, the CDK12.5 is an exceptional diffraction-limited telescope. CDK12.5 users can experience pinpoint stars edge-to-edge and a 70 x 70 arcminute field of view when using large 16803 size camera sensors. When equipment fades into the background and simply performs, the astrophotography experience becomes even more fun and rewarding!


Carbon Fiber Tube Design

Carbon Fiber Tube Design Minimizes thermal expansion which causes focus shift as temperature changes during an imaging session. Carbon fiber also reaches ambient temperatures quickly and is extremely lightweight and rigid to help ensure excellent imaging data is produced.

Dovetail Expansion Joint

Dovetail Expansion Joint Allows for the difference in thermal expansion between carbon fiber and aluminum. The expansion joint allows the aluminum dovetail to expand and contract without stressing the carbon fiber lower truss. This results in images that are not distorted due to expansion, or contraction of the optical tube materials.

2.75-inch Hedrick Focuser

2.75 inch Hedrick Focuser Heavy-duty no-slip focuser with 1.3" of drawtube travel when fully racked out. The focus tube runs on 5 bearings and is driven by a leadscrew, so there is no chance of slipping. Focusing is automated through PlaneWave Interface 3 (PWI3) software when using the sold separately PlaneWave Electronic Focuser Accessory. PWI3 performs fast and extremely accurate autofocusing routines to ensure your images are always at critical focus.

Cooling Fans

Cooling Fans Three fans blow out of the optical tube pulling air through the telescope and by the primary mirror. This helps the telescope to reach thermal equilibrium quickly. The fans are controlled by a switch on the optical tube, or can be controlled by via PWI3 software if a PlaneWave Electronic Focus Accessory (EFA Kit) is purchased.

Optical System

Aperture 12.5 inch (318 mm)
Focal Length 2541 mm (100.04 inch)
Focal ratio f/8
Central Obstruction 42% of the primary mirror diameter
Back Focus from Mounting Surface 10.445 inch (265 mm)
Back Focus from Racked in Focuser 7.2 inch (183 mm)
OTA Length 31 inch (787 mm)
Optical Tube Carbon fiber
Dimensions Overall Dimensions (PDF)
Weight (includes manual-focuser and dovetail) 46 lbs (20.9 kg)
Weight (includes electronic-focuser and dovetail) 48.5 lbs (22.0 kg)
Optimal Field of View 52mm image circle

Secondary Mirror

Diameter 4.65 inch (118 mm)
Material Fused silica (quartz)
Shape Spherical
Coating Enhanced aluminum – 96%

Primary Mirror

Optical Diameter 12.5 inch (318 mm)
Outer Diameter 13 inch (330 mm)
Shape Prolate ellipsoid
Material Fused silica (quartz)
Coating Enhanced aluminum – 96%

Lens Group

Diameter 70 mm (2.76 inch)
Number of lenses 2
Coating Broadband AR coatings (less than .5% reflected from 400 to 700nm)


Crated Shipping Weight 163 lbs   (73.9 kg)
Crate Width 22 inch   (559 mm)
Crate Height 29 inch   (737 mm)
Crate Length 48 inch   (1,219 mm)
Included Items

Included Items

Motorized 2.75″ Hedrick Focuser Offers 1.3″ of focuser travel and takes up 3″ of backfocus. Requires the 125901 EFA kit sold separately
Heating elements for dew prevention The heating pads on the primary and secondary mirror require the 600195 Delta-T controller sold separately
OTA Cover To protect the primary mirror and inside of the optical tube
Flashdrive Contains software and instructions for collimation and spacing the primary to secondary mirror
Cable connector for fan power Provides a connection method for powering for the fans if the user does not have the 125901 EFA kit. User must provide 12VDC powersupply 2.1 barrel jack connector that is center positive. (Not included for European orders)
Wrench Set (5812A35) Standard hex wrenches (European orders only)



Camera Adapters Diagrams

Drawings & Diagrams

Recommended Accessories

Reducer 0.66x for CDK12.5 (125166)

Finderscope Mounting Bracket (125360)

Finderscope and Mounting Bracket (200985)

Delta T Heater

EFA kit Electronic Focuser (200901)

Piggyback Dovetail CDK12.5 (12599)

Keller EZ-Saddle (600182)

Counterweight Accessory for CDK12.5 (125150)

L350 Direct Drive Mount (600549)