CDK24 Optical Tube Assembly
The CDK24 is an innovative telescope for unsurpassed astroimaging, research, or satellite tracking.
- f/6.5 and 3974mm focal length.
- No coma, no off-axis astigmatism, and no field curvature.
- Pinpoint stars across a 70mm 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.
Delta-T Ready – Now the CDK24 comes standard with built-in dew heaters for both primary and secondary mirror. A $550 value!
Introducing the PlaneWave Instruments CDK24, a 24 inch (0.61 m) f/6.5 Corrected Dall-Kirkham Astrograph telescope. The CDK24 has a dual truss design, with 3 cooling fans for the back of the primary mirror and 4 fans for the front surface of the primary mirror. The CDK24 covers a 70 mm field of view without any field curvature, off-axis coma, or astigmatism. The instrument weight is 240 lbs (109 kg) and comes standard with a back plate retaining ring ready to accept the focuser of your choice.
The CDK (Corrected Dall-Kirkham) Optical Design is an innovative solution for unsurpassed astroimaging quality at an affordable price. The CDK telescope design provides excellent imaging with large format cameras while remaining superb for visual use. The CDK design far exceeds the off-axis performance of most commercial telescope designs including the Ritchey-Chrétien design.
This no-compromise design is unique in making the optical alignment forgiving and collimation very easy. This guarantees the user the best possible performance from the telescope. The end result at the image plane of the CDK design is no off-axis coma, no off-axis astigmatism, perfectly flat field (no off-axis defocus). The CDK design will give you pinpoint stars from the center to the corner of the field of view. Checkout more about our technology and optical design here.
Fused Silica Optics
Fused Silica has a coefficient of thermal expansion six times lower than Borosilicate (Pyrex) glass, which means that as it cools down, fused silica preserves its shape to a high degree of accuracy. This translates into consistent optical performance and unchanging focus over temperature changes.
For added dew prevention, the CDK24 is internally wired with polyimide film heater pads and temperature sensor, ready to be controlled with the optional Delta-T controller.
Carbon Fiber Truss Design
Minimizes thermal expansion which causes focus shift with changes in temperature
Dovetail expansion joint
Allows for the difference in thermal expansion between carbon fiber and aluminum. The expansion joint allows the aluminum dovetail expand and contract without stressing the carbon fiber lower truss
Three cooling fans ejecting air from the back of the telescope and four fans blowing across the boundary layer of the mirror surface. This helps the telescope to reach thermal equilibrium quickly. The fans are controlled by a computer if the optional Electronic Focus Accessory (EFA Kit) is purchased.
|Aperture||24 inch (610 mm)|
|Focal Length||3974 mm (156.46 inch)|
|Central Obstruction||47% of the Primary Mirror Diameter|
|Back Focus from Mounting Surface||14.1 inch (358 mm)|
|Back Focus from Racked in Focuser||5.81 inch (148 mm)|
|Weight||240 lbs (108.9 kg)|
|OTA Length||56 inch (1,422 mm)|
|Upper Cage||Carbon Fiber Truss|
|Lower Cage||Carbon Fiber Truss with Aluminum Light Shroud|
|OTA Width||31 inch (787 mm)|
|OTA Height||35 inch (889 mm)|
|Optimal Field of View||70 mm (58 arcminute)|
|Diameter||11 inch (280 mm)|
|Coating||Enhanced Aluminum – 96%|
|Optical Diameter||24 inch (610 mm)|
|Outer Diameter||24.5 inch (622 mm)|
|Coating||Enhanced Aluminum – 96%|
|Diameter||135 mm (5.31 inch)|
|Number of lenses||2|
|Coating||Broadband AR Coatings (less than .5% reflected from 400 to 700nm)|
|Crated Shipping Weight||500 lbs (226.8 kg)|
|Crate Width||40 inch (1,016 mm)|
|Crate Height||48 inch (1,219 mm)|
|Crate Length||78 inch (1,981 mm)|
|CDK24 Focus Spacer (240343)||This 5.3″ long spacer may be installed between the backplate and the focuser to take up some of the CDK24’s extra backfocus and reduce the torque placed on the focuser mechanism. This spacer is sized such that the backfocus distance behind the focuser will match that of the CDK20.|
|Primary Mirror Cover||The Primary Mirror Cover protects the primary mirror.|
|Planewave thumb drive||Includes instructions for Collimation and Spacing and software.|
|12VDC Power Supply||Provides power for the fans (Not included for European Orders)|
|Wrench Set (5812A35)||English Hex Wrenches (European Orders Only)|
For warranty information please check our Standard Warranty Page
Drawings & Diagrams
- CDK24 Optical Tube Dimensions
- CDK24 Vignetting and Spot Size Plots
- CDK24 Piggyback Dovetail Plate Diagram
Camera Adapters Diagrams
- CDK24 IRF90 to Apogee Adapters
- CDK24 IRF90 to SBIG STX Adapters
- CDK24 to Apogee Adapters
- CDK24 to FLI Adapters
- CDK24 to SBIG Adapters