The PlaneWave 20" Optimised Dall-Kirkham has been design with coatings that are optimized to transmit in infrared or ultra violet wavelengths. It is diffraction limited across a 20mm image circle at the focal plane. There are no refractive lens, only reflective components to the design. For IR application, reflectives coatings are a protected gold which give better than 98% reflectivity from .65 micron (650nm) to 5 micron (5000nm). This design is ideal for infrared astronomy or LIDAR applications. UV optimized coatings can also be used at an additional cost.
OPTICAL SYSTEM
| Aperture | 20" (.51m) |
| Focal Length | 3454 mm |
| Central Obstruction | 39% of the Primary Mirror Diameter |
| Back Focus | 8.9" from focuser mounting surface, 5.81" from racked in focuser |
| Weight | 140 lbs |
| OTA Length | 47" |
| Upper Cage | Carbon Fiber Truss |
| Lower Cage | Carbon Fiber Truss with Carbon Fiber light shroud |
| Dimensions | Overall Dimensions |
SECONDARY MIRROR
| Diameter | 7.5" |
| Material | Precision Annealed Pyrex |
| Shape | Spherical |
| Coating | Protected Gold Reflective Coating - 98% (.65-16micron) |
SECONDARY MIRROR
| Material | Precision Annealed Pyrex |
TERTIARY MIRROR
| Material | Precision Annealed Pyrex |
STANDARD FEATURES
| Carbon Fiber Truss Design | Minimizes thermal expansion which causes focus shift with changes in temperature |
| Dovetail expansion joint | Allows for the difference in thermal expansion between carbon fiber and aluminium. The expansion joint allows the aluminium dovetail expand and contract without stressing the carbon fiber lower truss |
| Cooling Fans | Three cooling fan blow out of the optical tube pulling air though the telescope and pass the primary mirror. This helps the telescope to reach thermal equilibrium quickly. The fans are controlled by a computer if the optional Electronic Focus Accessory (EFA Kit) is purchased. |
SHIPPING
| Crated Shipping Weight | 291 lbs (132.0 kg) |
| Crate Width | 32 inch (813 mm) |
| Crate Height | 36 inch (914 mm) |
| Crate Length | 59 inch (1,499 mm) |
NOTE: This item has a lengthy leadtime. for more details email: education@bintel.com.au