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CDK20 Astrograph f/6.8 with Fused Silica Optics

# 1323220Q
Price: € 34,200.00
(Price incl. German VAT excl. shipping)

PlaneWave CDK20 Astrograph f/6.8

The 20" CDK is a revolutionary new telescope optical system that is designed to excel at imaging on large format CCD cameras while remaining an excellent instrument for visual use.

One of the unique features of the CDK design is its ease of collimation and achievable centering tolerance for a telescope of its class. This assures the user will get the best possible performance out of the telescope. The end result is a telescope which is free from off-axis coma, off-axis astigmatism, and curvature of field, yielding a perfectly flat field all the way out to the edge of a 52mm image circle.

The PlaneWave CDK 20 is available in various types of mirror material. Standard mirror material is borosilicate. The telescope is also available in fused silica optics, Ritchey-Chrétien (RC) optics and infrared optimized.

  • CDK 20 Astrograph, 20 inch with Fused Silica Optics
  • modified to Dall-Kirkham, with fully corrected image field
  • with 8" Dovetail, focal length 3.454 mm (f/6,8), 52 mm field of view
  • Delta T Ready, 3,5" Hedrick Focuser and EFA Kit separately available
  • Requires a crating #1323520. The crating will be charged extra


Fused Silica
Spot diagrams
Scope of delivery


Optical Design
Corrected Dall-Kirkham (CDK)
Aperture (mm)
20" (508 mm)
Focal Length
3.454 mm (135.98 inch)
Focal Ratio
Image Field
52 mm
Back Focus Distance
5.8" (147 mm) from Racked in Focuser
Central Obstruction
39% of the Primary Mirror Diameter
Fused Silica
Optical length
47 inch (1.194 mm)
Optical Tube Weight
140 lbs (64 kg)
No mount (OTA only)
Manufacturer SKU
EAN Code

PlaneWave Live: CDK20 Astrograph f/6.8


We reserve the right for errors and technical changes. For the latest information visit directly the manufacturer's website