PlaneWave CDK20 Astrograph f/7.77 with Fused Silica Optics (1323222Q)

PlaneWave CDK20 Astrograph f/7.77 with Fused Silica Optics

Description:
The PlaneWave CDK20 is a 20-inch telescope optical system designed to excel in imaging with large format CCD cameras while remaining an outstanding visual instrument.

Capturing the most stunning astrophotographs possible is something the PlaneWave team is passionate about. From design to manufacturing, the goal with the CDK20 telescope was centered around performance and ease of use. The CDK20 is a major breakthrough in telescope technology and produces no off-axis coma and no off-axis astigmatism. Additionally, the CDK20 provides a perfectly flat field so your astrophotos will have stunning clarity from corner to corner without field curvature degrading the image. Offering single-mirror collimation, stray light control from advanced baffles, structural performance via finite element analysis (FEA), and decades of telescope design experience, the CDK20 is a diffraction-limited instrument. It offers pinpoint stars across a 45 x 45 arcminute field with large 16803-size camera sensors. When equipment fades into the background and just performs, the astrophotography experience becomes even more enjoyable and rewarding.

The CDK20 is also available with Ritchey-Chrétien (RC) optics and infrared-optimized configurations.

This version of the CDK20 with Fused Silica optics offers 1.9″ more back focus and 497 mm more focal length than the standard CDK20 f/6.8.

It is modified to the Dall-Kirkham design with a fully corrected image field, an 8" dovetail, a focal length of 3951 mm (f/7.77), and delivers pinpoint stars across a 52 mm image circle.

It is Delta-T Ready. The 3.5" Hedrick focuser and EFA Kit are available separately. Crating requires reference #1323520 (charged separately).

Carbon Fiber Truss Design:
Minimizes thermal expansion that can cause focus shift during imaging sessions. Carbon fiber reaches ambient temperature quickly and is extremely lightweight and rigid, helping ensure excellent imaging data.

3D Printed Baffles:
PlaneWave uses digital 3D printing to produce lightweight baffle tubes. These are built layer by layer to create precisely positioned internal baffles that reduce vignetting and maximize contrast. Quality baffling significantly improves overall image quality.

Dovetail Expansion Joint:
This joint compensates for the thermal expansion difference between carbon fiber and aluminum. It allows the aluminum dovetail to expand and contract without stressing the lower carbon truss, preserving image quality despite temperature variation.

Delta-T Ready:
The CDK20 is internally wired with polyimide film heater pads and temperature sensors, ready to be controlled via PlaneWave Interface 3 software for effective dew prevention.

Cooling Fans:
Three fans on the backplate pull air through the telescope and past the primary mirror. Three more fans on the side blow air across the mirror, preventing distortion from boundary layers. Fans are controlled via a switch or PWI3 software (with EFA Kit).

Specifications:

Optical design: Corrected Dall-Kirkham (CDK)
Aperture: 20" (508 mm)
Focal length: 3951 mm (155.55")
F-ratio: f/7.77
Image field: 52 mm
Back focus: 10.7" (271.98 mm) from mounting surface
Central obstruction: 39% of the primary mirror diameter
Substrate: Fused Silica
Optical length: 47" (1194 mm)
OTA weight: 140 lbs (63.5 kg)
Dovetail: 8"
Delta-T Ready: yes (controller sold separately)
Cooling system: 3 rear fans + 3 side fans
Structure: carbon fiber truss with 3D printed internal baffles
Crate required: reference #1323520 (charged separately)