About this product
Model: cel_r-a_astrograph_14_ota
Part Number: 91078-CGL
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.
This large astrograph telescope is delivered on a pallet direct from Celestron's UK warehouse. It is manufactured in limited numbers, so please contact us for current availability (lead times are subject to change).
The Celestron RASA 36 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.
- 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 colour, coma, and field curvature, RASA 36 cm is also an excellent choice for advanced astroimaging.
- The New Ultra-Stable Focus System (USFS) minimises focus shift, mirror flop, and any other unwanted motion of the primary mirror, enabling easy and dependable focus.
- 60 mm optimised 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.
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 minimises 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 range of imaging sensors. You may add a custom camera adapter for a field of view up to 4.4 degrees.
Additional feature
- Celestron’s proprietary XLT coatings, consisting of high-transmission multi-coatings for lenses and high-reflectivity aluminium 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 easily 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
NOTES:
The RASA 36 is a professional-calibre, high-precision instrument manufactured and aligned to an exacting standard to provide exceptional optical performance. The telescope has sturdy packaging and is delivered on a pallet to ensure it arrives safely and retains its optical alignment.
The RASA optical system is designed for astrophotography. It cannot be used visually. The prime focus focal plane is located at the front of the optical system, so it cannot accommodate a traditional eyepiece.
RASA telescopes are best suited to experienced astronomers. If you are unsure whether one will suit your requirements, please get in touch with us before placing an order.
Rowe-Ackermann Tour (Shows 11" model)
Specifications
Optical design | Rowe-Ackermann Schmidt |
Aperture | 355.6 mm (14") |
Focal length | 790 mm (31.1") |
Focal ratio | f/2.2 |
Resolution (Rayleigh) | 0.39 arc seconds |
Resolution (Dawes) | 0.36 arc seconds |
Light gathering power (compared to the human eye) | 2581x |
Central obstruction diameter | 158mm (6.22") (44% of aperture diameter) |
Imaging circle | 60.1mm (2.36") Ø, 4.4° |
Usable 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 |
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 the top of threaded collar | 77.5mm (3.05") |
Optical tube material | Aluminium |
Optical tube length | 1079.5mm (42.5") |
Optical tube diameter | 406.4mm (16") |
Focuser | Ultra-Stable Focus System (USFS) |
Optical tube weight | 75 lbs (34.02 kg) |
Other features | Ventilation fan, dual CGE dovetail mounting bars |
Optical coatings | StarBright XLT |
Included items | 48mm (1.89") camera adapter, fan battery pack |
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