36cm Rowe-Ackermann Schmidt Astrograph (91077)
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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.
|Optical design||Rowe-Ackermann Schmidt Astrograph|
|Clear aperture||355.6 mm|
|Focal Length||790 mm|
|Central obscuration||158 mm (44% of aperture diameter)|
|Image circle||60.1 mm Ø, 4.3°|
|Useable field||70 mm Ø, 5.1°, only minimal performance loss at edge of FOV|
|Wavelength range||400 – 900 nm|
|Spot size||< 6.3 μm RMS across FOV|
|Optical coatings||Enhanced aluminum, XLT multi-coatings used throughout|
|Off-axis Illumination||83% at 30 mm off-axis|
|Optical filter||104 mm Ø|
|Back focus (with included adapter)||55 mm|
|Back focus (from top of threaded collar)||77.5 mm|
|Tube dimensions||42.5" length, 16" diameter, 75 lbs|
|Focuser||New focuser design, minimizes focus shift|
|Other features||Ventilation fan, dual dovetail mounting bars|