36 cm Rowe-Ackermann Schmidt Astrograph (RASA 36) Optical Tube Assembly (CGE Dovetail)
Item #: 91077- A breakthrough 36 cm aperture, f/2.2 optical system designed for professional applications that require both a wide field of view and resolution, such as space surveillance and other scientific applications
- 4-element lens group utilizes extra-low dispersion (ED) glass for images free of false color, coma, and field curvature, the Rowe-Ackermann Schmidt Astrograph (RASA) 36 cm is also an excellent choice for advanced astroimaging
- 60 mm optimized image circle maintains pinpoint stars to the far corners of the largest available sensors
- Extended spectral range takes advantage of sensor response in the 700-900 nm range, allowing a brighter overall signal to be detected
- Redesigned focusing system minimizes focus shifting or other unwanted motion of the primary mirror, enabling easy and stable focus
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, such as space surveillance and other scientific applications
- 4-element lens group utilizes extra-low dispersion (ED) glass for images free of false color, coma, and field curvature, the Rowe-Ackermann Schmidt Astrograph (RASA) 36 cm is also an excellent choice for advanced astroimaging
- 60 mm optimized image circle maintains pinpoint stars to the far corners of the largest available sensors
- Extended spectral range takes advantage of sensor response in the 700-900 nm range, allowing a brighter overall signal to be detected
- Redesigned focusing system minimizes focus shifting or other unwanted motion of the primary mirror, enabling easy and stable focus
Includes These Celestron Technologies
Description
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 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.
Technology
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. Accomodates “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
- Motor system specifically designed for the RASA 36 cm focuser is manufactured by Starlight Instruments.
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: | New focuser design, minimizes focus shift |
| 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 |
Videos
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."
Read Full Review
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.
Support & Downloads
