PlaneWave CDK17 f/6.8 Optical Tube Assembly The CDK17 is a 432 mm Corrected Dall-Kirkham astrograph with a 2939 mm focal length and a flat, coma- and astigmatism-free 70 mm image circle, built for research and advanced deep-sky imaging.
Manufacturer model: PlaneWave CDK17 f/6.8 OTA (170101Q) · Specifications checked against manufacturer data on 2026-11-03
The CDK17 is a 432 mm Corrected Dall-Kirkham astrograph with a 2939 mm focal length and a flat, coma- and astigmatism-free 70 mm image circle, built for research and advanced deep-sky imaging.
Fused silica mirrors and a carbon fibre truss minimise focus shift with temperature. Cooling fans and a Delta-T-ready dew system keep the optics stable and clear.
| Optical design | Corrected Dall-Kirkham |
|---|---|
| Aperture | 432 mm (17") |
| Focal length | 2939 mm |
| Focal ratio | f/6.8 |
| Central obstruction | 23.7% by area; 48.6% of primary diameter |
| Image circle | 70 mm |
| Optical performance | 6.5 µm RMS at 21 mm; 9.6 µm at 26 mm off-axis |
| Primary mirror | 432 mm optical / 445 mm outer, prolate ellipsoid, fused silica, enhanced aluminium 96% |
| Secondary mirror | 190 mm spherical, fused silica, enhanced aluminium 96% |
| Corrector lenses | 105 mm, broadband AR (<0.5% reflection, 400–700 nm) |
| Back focus from mounting surface | 262.33 mm (10.32") |
|---|---|
| Back focus from racked-in focuser | 184 mm (7.24") |
| OTA length | 1067 mm (42") |
| Weight | 48 kg (106 lb) |
| Upper / lower cage | Carbon fibre truss / carbon fibre truss with light shroud |
Current CDK17 design (10.32in back focus), not IRDK17. Uses PlaneWave Wide Saddle on L-500/L-550.
| Bf focuser (mm) | 184 |
|---|
Ficha técnica
PlaneWave CDK17 f/6.8 Optical Tube Assembly The CDK17 is a 432 mm Corrected Dall-Kirkham astrograph with a 2939 mm focal length and a flat, coma- and astigmatism-free 70 mm image circle, built for research and advanced deep-sky imaging.
Manufacturer model: PlaneWave CDK17 f/6.8 OTA (170101Q) · Specifications checked against manufacturer data on 2026-11-03
