Prices do not include shipping costs. Contact us for exact shipping prices before purchasing. The PlaneWave Instruments IRDK20 is an infrared-optimized Dall-Kirkham telescope for advanced astronomical research and environmental LIDAR applications. With gold-plated fused silica mirrors with no refractive lenses, the IRDK20 averages 94% reflectivity across 0.7 - 2.5 microns (700 - 2500nm). The IRDK20 excels in infrared astronomy thanks to its large aperture and IR-optimized optics. In addition to studying astrophysical phenomena in the infrared, the IRDK series offer a robust platform for LIDAR and remote sensing operations. Features Carbon fibre tube minimizes thermal expansion, which causes focus shift as temperature changes during an imaging session. Carbon fibre also reaches ambient temperatures quickly and is extremely lightweight and rigid to help ensure excellent imaging data is produced. Dovetail expansion joint allows for the difference in thermal expansion between carbon fiber and aluminium. The expansion joint allows the aluminium dovetail to expand and contract without stressing the carbon fiber lower truss. Integrated dew control including heater pads controllable via PlaneWave's software and the Delta-T controller (sold separately) keep the optical surfaces clear of dew, ensuring consistent and clear imaging performance. Three cooling fans blow out of the optical tube pulling air through the telescope and by the primary mirror. This helps the telescope to reach thermal equilibrium quickly. The fans are controlled by a switch on the optical tube, or can be controlled by via PWI3 software. All PlaneWave telescopes feature the following ports for dew heater and fan management: Two RCA connectors to power the dew heater (from the Delta T or from a 12V source) One RJ connector for the Delta T to the telescope to transmit temperature data One EFA connector to power the fans (EFA to 5.5-2.1 jack included) One auxiliary output port The built-in dew heaters can be powered by any 12V DC source which has an RCA connector, but the Delta T is required to keep the mirror just above the dew point to avoid overheating and the resulting internal turbulences. The EFA connector can be powered by the separate EFA controller, any 12V DC source using the supplied EFA to 5.5 x 2.1 jack, or by the Series-5 controller. Specifications Aperture 20" (508 mm) Focal length 3454 mm Focal ratio f/6.8 Central obstruction 39% Backfocus from mounting surface 224 mm OTA length 1194 mm Optimal field of view 52 mm image circle Weight (OTA only) 63.5 kg Primary mirror Optical diameter 508 mm Outer diameter 521 mm Material Fused silica (quartz) Shape Prolate ellipsoid Coating Protected Gold - 94% Secondary mirror Diameter 191 mm Material Fused silica (quartz) Shape Spherical Coating Protected Gold - 94% Included items IRDK20 OTA OTA cover to protect primary mirror Printed instructions
