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Model: 91077Brand: Celestron
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The Rowe-Ackermann Schmidt Astrograph (RASA), is a cost-effective optical system for space surveillance, Space Situational Awareness (SSA), other scientific applications, and advanced wide field astroimaging. It offers unprecedented value in aperture, speed, field of view, and optical performance. The RASA design has a convenient external prime-focus image capture location with a flat focal plane, providing small spot sizes to the edge of a wide field. The result is images free of optical defects like field curvature, off-axis coma, and astigmatism.
The 36 cm aperture version is the largest RASA Celestron manufactures; it is the biggest and fastest (f/2.2) optical instrument of its kind available “off-the-shelf.” Unlike most telescopes, which only focus visible light (400-700 nm), the RASA 36 cm focuses an extended spectral range (400-900 nm), allowing a brighter signal to be detected by a camera sensor. The RASA 36 cm also features a redesigned focus system, which ensures easy and stable focusing.
RASA 36 cm’s ample back-focus distance (77.5 mm) accommodates a wide variety of imaging sensors. A custom camera adapter can be added for a field of view up to 4.4 degrees.
Important freight requirement – RASA 36 is a professional-caliber, high-precision instrument. It is manufactured and aligned to an exacting standard to provide exceptional optical performance. The telescope has been packaged to ensure it retains alignment and resulting performance during transport. However, due to the weight, size, and known stresses of shipping via parcel service, Celestron has determined that the ideal transport is a palletized delivery.
Additional FeaturesCelestron’s proprietary XLT coatings, consisting of high-transmission multi-coatings for lenses and high reflectivity aluminum coatings, ensure good light throughput for the optical systemIntegrated cooling fan helps optics cool down to ambient temperature and pulls air through vents with micromesh to prevent dust ingressDual dovetail bars offer flexibility to mount the optical tube and conveniently attach additional accessories. Accomodates “CGE/Losmandy” style dovetails.Two sets of 2x threaded insert holes in the rear cell provide additional mounting optionsMove and mount your optical tube with ease with carrying handles on the rear cellAlthough not normally needed, there are 3x sets of push-pull screws to adjust the lens group to achieve optical alignment for the entire systemIncludes M48 camera adapterMotor system specifically designed for the RASA 36 cm focuser is manufactured by Starlight Instruments.
OPTICAL TUBE INFO: Optical Design Rowe-Ackermann Schmidt AstrographAperture 355.6mm (14")Focal Length 790mm (31.1")Focal Ratio f/2.2Central obstruction diameter 158mm (6.22")(44% of aperture diameter)Light Gathering Power (Compared to human eye) 2581XResolution (Rayleigh) 0.39 arc secondsResolution (Dawes) 0.36 arc secondsImage circle 60.1mm (2.36") Ø, 4.4°Useable field 70mm (2.75") Ø, 5.1°, only minimal performance loss at edge of FOVWavelength range 400 – 900 nmSpot size < 6.3 μm RMS across FOVOptical coatings Enhanced aluminum, XLT multi-coatings used throughoutOff-axis Illumination 83% at 30mm (1.18") off-axisOptical window 104mm (4.09") ØBack focus with included camera adapter 55mm (2.16")Back focus from top of threaded collar 77.5mm (3.05")Optical Tube AluminumOptical Tube Length 1079.5mm (42.5")Optical Tube Diameter 406.4mm (16")Focuser New focuser design, minimizes focus shiftFinderscope Not includedOptical Tube Weight 75 lbs (34.02 kg)Other features Ventilation fan, dual dovetail mounting barsIncluded items 48mm (1.89") camera adapter, fan battery pack
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