Hubble 10, 12.5, 17, 20-inch CDK (Corrected Dall-Kirkham), and beyond:

  • The Hubble corrected Dall-Kirkham (CDK) optical configuration, as developed over the last 13 years by Dave Rowe, is a revolutionary optical design.
  • It is an affordable, high performance solution for astrophotography and visual use, with a large, flat focal surface that is perfect for modern, high resolution, CCD cameras.
  • Outstanding Images - Premium quality, diffraction limited Newtonian optical systems will deliver stunning views of the heavens from dark sky sites.
  • Historically: the SCT has been the industry-standard visual, film and small CCD imaging telescope for popular astronomy since the mid-70s. However, the standard SCT has a highly curved focal surface and suffers from considerable comatic aberration, which limits its useful photographic field to a relatively small image circle. For instance, a 10” all spherical SCT can provide 10-micron spot sizes over only a very small field of about 9mm diameter, which is clearly not suitable for today’s high resolution, large format CCDs.
  • Combined with our revolutionary sandwich primary, Our CDK 10" and 12.5" optics will bring you superior optical performance in real world situations, even without an active cooling system (Active cooling systems, such as fans, introduce their own serious problems, such as micro vibration, which will degrade the image quality more or less). Our mirrors reach equilibrium extremely fast, and without aid.
  • The CDK12.5 primary mirror is made with our revolutionary sandwich mirror. The CDK10 is made with plate or Pyrex solid blank.
  • Our 2-section (completely CNC machined) closed tube OTA prototype is not only optimized to reach a zero thermal focal shift, but is also structurally much stronger than a single section tube.

Gallery


Hubble CDK10 f/8 Specification:

  • System Focal Ratio: 8
  • Field Of View: 45mm
  • Obstruction Ratio: 38%
  • Back Focus (from the last surface of the corrector lens): 253mm
  • Suggested Focuser Diameter: 2"
  • Primary Mirror:
    • Optical Diameter: 254mm (overall diameter 266mm)
    • Weight: ~4kg
    • Thickness: ~45mm
    • Focal Ratio: f/3
    • 92% Semi-enhanced coated
    • Strehl Ratio 0.95 or better.
  • Secondary Diameter: 95mm
    • 96% enhanced coated.
  • Corrector Optics:
    • 99.5% broadband coated.
  • Delivery Time: ~90Days


Hubble CDK12.5 f/8 Specification:

  • System Focal Ratio: 8
  • Field Of View: 60mm
  • Obstruction Ratio: 42%
  • Back Focus (from the last surface of the corrector lens): 318mm
  • Suggested Focuser Diameter: 3"
  • Primary Mirror:
    • Optical Diameter: 317.5mm (overall diameter 344mm)
    • Weight: ~6kg
    • Thickness: ~40mm
    • Focal Ratio: f/3
    • 92% Semi-enhanced coated
    • Strehl Ratio 0.95 or better.
  • Secondary Diameter: 120mm
    • 96% enhanced coated.
  • Corrector Optics:
    • 99.5% broadband coated.
  • Delivery Time: ~90Days


Hubble CDK17 f/6.8 Specification:

  • System Focal Ratio: 6.8
  • Field Of View: 60mm
  • Obstruction Ratio: 39%
  • Back Focus (from the last surface of the corrector lens): 341mm
  • Suggested Focuser Diameter: 3"
  • Primary Mirror:
    • Optical Diameter: 432mm
    • Weight: ~13kg (Plate Glass), ~12kg (Pyrex)
    • Thickness: ~55mm
    • Focal Ratio: f/3
    • 92% Semi-enhanced coated
    • Strehl Ratio 0.95 or better.
  • Secondary Diameter: 160mm
    • 96% enhanced coated.
  • Corrector Optics:
    • 99.5% broadband coated.
  • Delivery Time: ~90Days


Hubble CDK20 f/6.8 Specification:

  • System Focal Ratio: 6.8
  • Field Of View: 70mm
  • Obstruction Ratio: 39%
  • Back Focus (from the last surface of the corrector lens): 341mm
  • Suggested Focuser Diameter: 3"
  • Primary Mirror:
    • Optical Diameter: 500mm
    • Weight: ~20kg (Plate Glass), ~18kg (Pyrex)
    • Thickness: ~55mm
    • Focal Ratio: f/3
    • 92% Semi-enhanced coated
    • Strehl Ratio 0.95 or better.
  • Secondary Diameter: 160mm
    • 96% enhanced coated.
  • Corrector Optics:
    • 99.5% broadband coated.
  • Delivery Time: ~90Days


Payment

To buy CDK Optics(Primary, Secondary Mirrors and Corrector) and also find out shipping costs, please e-mail us!

Diameter CDK Optics with Plate Primary(US$) CDK Optics with Pyrex Primary(US$)
CDK10 1200 1600
CDK12.5 f/8 1950 2495
CDK17 f/6.8 5500 6700
CDK20 f/6.8 8000 10500
CDK24 f/6.8 13500 16950
CDK40 f/6 Contact Us Contact Us
CDK80 f/6 Contact Us Contact Us