36 cm Rowe-Ackermann Schmidt Astrograph (RASA 36) V2 Optical Tube Assembly (CGE Dovetail)
Item #: 91078 / 91078-CGL- A breakthrough 36 cm aperture, f/2.2 optical system designed for professional applications that require both a wide field of view and resolution, the Rowe-Ackermann Schmidt Astrograph (RASA) 36 cm is ideal for space surveillance and other scientific applications.
- With a 4-element lens group featuring extra-low dispersion (ED) glass for images free of false color, coma, and field curvature, RASA 36 cm is also an excellent choice for advanced astroimaging.
- New Ultra-Stable Focus System (USFS) minimizes focus shift, mirror flop, and any other unwanted motion of the primary mirror, enabling easy and dependable focus.
- 60 mm optimized image circle maintains pinpoint stars to the far corners of the largest available sensors.
- An extended spectral range takes advantage of sensor response in the 700-900 nm range, allowing a brighter overall signal to be detected.
Overview
- A breakthrough 36 cm aperture, f/2.2 optical system designed for professional applications that require both a wide field of view and resolution, the Rowe-Ackermann Schmidt Astrograph (RASA) 36 cm is ideal for space surveillance and other scientific applications.
- With a 4-element lens group featuring extra-low dispersion (ED) glass for images free of false color, coma, and field curvature, RASA 36 cm is also an excellent choice for advanced astroimaging.
- New Ultra-Stable Focus System (USFS) minimizes focus shift, mirror flop, and any other unwanted motion of the primary mirror, enabling easy and dependable focus.
- 60 mm optimized image circle maintains pinpoint stars to the far corners of the largest available sensors.
- An extended spectral range takes advantage of sensor response in the 700-900 nm range, allowing a brighter overall signal to be detected.
Includes These Celestron Technologies
Description
The Rowe-Ackermann Schmidt Astrograph (RASA) V2 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. Images are free of optical defects like field curvature, off-axis coma, and astigmatism.
Optical Performance
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.
Advanced Features
RASA 36 V2 features the new Ultra-Stable Focus System (USFS). At the heart of this system is a precision linear ball bearing. The bearing minimizes focus shift (unwanted lateral movement of the primary mirror during focusing, which causes shifting of the image) and mirror flop (movement of the primary mirror when the telescope is pointing to different positions in the sky). The USFS is compatible with the optional Celestron Focus Motor (#94155-A). The integrated 12V DC MagLev fan reduces cooldown time and provides optimal airflow through the dust-filtered optical tube. RASA 36 cm’s ample back-focus distance (77.5 mm) accommodates a wide variety of imaging sensors. You may add a custom camera adapter for a field of view up to 4.4 degrees.
Additional Features
- Celestron’s proprietary XLT coatings, consisting of high-transmission multi-coatings for lenses and high-reflectivity aluminum coatings, ensure good light throughput for the optical system.
- Integrated cooling fan helps optics cool down to ambient temperature and pulls air through vents with micromesh to prevent dust ingress.
- Dual dovetail bars offer flexibility to mount the optical tube and conveniently attach additional accessories. Accommodates “CGE/Losmandy” style dovetails.
- Two sets of 2x threaded insert holes in the rear cell provide additional mounting options
- Move and mount your optical tube with ease with carrying handles on the rear cell.
- Although not normally needed, there are 3x sets of push-pull screws to adjust the lens group to achieve optical alignment for the entire system.
- Includes M48 camera adapter
Important freight requirement – RASA 36 cm is a professional-caliber, high-precision instrument. Our technicians manufacture and align each RASA 36 cm to an exacting standard to provide exceptional optical performance. We package the telescope to ensure it retains alignment and 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 via LTL truck freight. For all domestic deliveries, Celestron will ship via this method. We also require this shipping method for all deliveries from Celestron dealers to end customers.
Specifications
| Optical Tube Info: | |
|---|---|
| Optical Design: | Rowe-Ackermann Schmidt Astrograph |
| Aperture: | 355.6mm (14") |
| Focal Length: | 790mm (31.1") |
| Focal Ratio: | f/2.2 |
| Central obstruction diameter: | 158mm (6.22")(44% of aperture diameter) |
| Light Gathering Power (Compared to human eye): | 2581X |
| Resolution (Rayleigh): | 0.39 arc seconds |
| Resolution (Dawes): | 0.36 arc seconds |
| Image circle: | 60.1mm (2.36") Ø, 4.4° |
| Useable field: | 70mm (2.75") 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-Coated throughout |
| Off-axis Illumination: | 83% at 30mm (1.18") off-axis |
| Optical window: | 104mm (4.09") Ø |
| Back focus with included camera adapter: | 55mm (2.16") |
| Back focus from top of threaded collar: | 77.5mm (3.05") |
| Optical Tube: | Aluminum |
| Optical Tube Length: | 1079.5mm (42.5") |
| Optical Tube Diameter: | 406.4mm (16") |
| Focuser: | Ultra-Stable Focus System (USFS), minimizes lateral movement of primary mirror |
| Finderscope: | Not included |
| Optical Tube Weight: | 75 lbs (34.02 kg) |
| Other features: | Ventilation fan, dual dovetail mounting bars |
| Included Items: |
48mm (1.89") camera adapter Fan battery pack |
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Reviews
Sky & Telescope’s Hot Products 2019 Award
"Incredibly fast optical speeds allow deep-sky imaging with short exposures, opening up a new world of scientific- and recreational-astrophotography possibilities."
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Accessories
FAQ
What is the heaviest recommend load for mounting a camera onto the RASA 36cm?
We recommend a load of no more than 38 lbs. at 5.6 inches away from the 14" Schmidt corrector.
Is there any preferred way of focusing my RASA 36cm to ensure sharpest stars at the edges of a large sensor?
Final focusing of the RASA 36cm should always be done by rotating the focus knob counter-clockwise (CCW). This direction of focus opposes the pull of gravity on the primary mirror, which provides the most stable focus. This also places the primary mirror in the optimal position for best optical performance at F/2.2 and provides best star images at the very edge of the huge 60mm image circle.
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