PlaneWave DeltaRho 350 f/3 Optical Tube Assembly The DeltaRho 350 is a fast 350 mm, f/3 corrected-Cassegrain astrograph with a 1050 mm focal length and a flat 60 mm image circle covering more than 3 degrees. Its speed and field suit wide-field deep-sky imaging as well as space situational and domain awareness (SSA/SDA) surveys.
Manufacturer model: PlaneWave DeltaRho 350 f/3 OTA · Specifications checked against manufacturer data on 2026-11-03
The DeltaRho 350 is a fast 350 mm, f/3 corrected-Cassegrain astrograph with a 1050 mm focal length and a flat 60 mm image circle covering more than 3 degrees. Its speed and field suit wide-field deep-sky imaging as well as space situational and domain awareness (SSA/SDA) surveys.
Carbon fibre truss poles and shroud keep the tube light and thermally stable. Collimation software supports quick, accurate alignment, and the primary and secondary mirrors carry dew heaters for the Delta-T controller.
| Optical design | Corrected Cassegrain focus |
|---|---|
| Aperture | 350 mm |
| Focal length | 1050 mm |
| Focal ratio | f/3 |
| Central obstruction | 56% by diameter |
| Image circle | 60 mm (>3°) |
| Optical performance | 4.9 µm RMS on-axis; 5.6 µm at 23 mm; 6.4 µm at 30 mm off-axis |
| Primary mirror | 350 mm optical, prolate ellipsoid, fused silica, enhanced aluminium 96% |
| Secondary mirror | 190 mm spherical, fused silica, enhanced aluminium 96% |
| Corrector lenses | 110 mm, broadband AR (<0.5% reflection, 400–700 nm) |
| Back focus from mounting surface | 142.24 mm (5.6", includes filter refraction); 64.135 mm with Series-5 focuser and rotator |
|---|---|
| OTA length | 584 mm (23") |
| Weight | 21 kg (46 lb) |
| Tube | Carbon fibre truss poles with carbon fibre shroud |
PlaneWave lists back focus as 143.535 mm (features) and 142.24 mm (spec table); table value used. Losmandy D dovetail; Keller EZ saddle on L-350. Series-5 focuser and rotator optional.
| Bf series5 (mm) | 64.135 |
|---|
Data sheet
PlaneWave DeltaRho 350 f/3 Optical Tube Assembly The DeltaRho 350 is a fast 350 mm, f/3 corrected-Cassegrain astrograph with a 1050 mm focal length and a flat 60 mm image circle covering more than 3 degrees. Its speed and field suit wide-field deep-sky imaging as well as space situational and domain awareness (SSA/SDA) surveys.
Manufacturer model: PlaneWave DeltaRho 350 f/3 OTA · Specifications checked against manufacturer data on 2026-11-03
