The night sky, at f/2.2.
The smallest Rowe-Ackermann Schmidt Astrograph ever built. Ultra-fast prime-focus optics, sub-arcsecond resolution and 3.8 kg of grab-and-go portability for serious deep-sky astrophotography, anywhere.
Professional optics. In a body you can carry with one hand.
Patented Rowe-Ackermann Schmidt architecture.
The RASA places the camera at prime focus, the same position used by professional wide-field survey telescopes. No secondary mirror, no Barlow, no lost light. More photons reach your sensor, in less time.
Since RASA technology debuted in 2014, defence contractors, professional researchers and governments have relied on it for space surveillance and satellite tracking. The RASA 6 delivers that same proven design in a portable package.
- Schmidt corrector plate and primary mirror minimise optical aberrations across the field
- Three-element rare-earth glass lens group ensures sharp, flat focus edge-to-edge
- Spot size under 1.5 μm RMS across the full image circle
NGC 6888. The Crescent Nebula.
Captured with the RASA 6 and an astronomical CMOS camera. Short sub-exposures stack into stunning images in a fraction of the time needed by slower instruments.
Four reasons it’s unlike anything else in its class.
Speed, resolution, portability and field of view, all engineered into one compact prime-focus astrograph.
Lightning-fast astrophotography at f/2.2.
The RASA 6’s blazing focal ratio dramatically shortens sub-exposure times. Faint deep-sky objects that would take hours with a typical refractor can be captured in a fraction of that time. Paired with live-stacking software, bright detailed images appear on your screen in just minutes. In many conditions you can image without an autoguider, simplifying your entire setup.
Sub-arcsecond potential.
Despite its compact size the 152 mm aperture delivers a Dawes resolution of 0.76 arc seconds. Pair it with a high-resolution CMOS camera in steady seeing and you will resolve fine structure in galaxies, nebulae and star clusters that smaller instruments cannot touch. The flat field means stars stay sharp from the centre all the way to the corner of the sensor.
Grab-and-go, genuinely.
At 3.8 kg the RASA 6 is light enough to carry with one hand and fits in a bag alongside your mount. The CG-5 dovetail means it drops straight onto most mid-range tracking mounts without adapters. Chase dark skies without compromising on optical performance. This is the astrograph you will actually take with you.
Wide field without sacrifice.
The RASA 6 is designed for sensors up to 22 mm diagonal, delivering a useable field of 3.76°. Wide enough to frame the Orion Nebula, the Pleiades and large emission nebulae in a single shot. Off-axis illumination of 91% at 8 mm means the field stays bright from edge to edge, reducing processing time on flats and vignette correction.
StarBright XLT. Maximum light throughput.
Every refractive and reflective surface is treated with Celestron’s proprietary StarBright XLT multi-layer coating. The result is exceptional light transmission and superior field illumination across the full wavelength range from 400 to 700 nm.
The RASA design outperforms a Schmidt-Cassegrain in Fastar-style configuration for field illumination. Less vignette, less processing, more imaging.
M42. The Orion Nebula.
IMX183C colour CMOS camera. 60 × 2 min exposures plus 20 × 15 sec exposures for the bright core. The wide field and fast optics of the RASA 6 capture the full extent of the nebula in a single frame.
Everything the modern astroimager needs, integrated.
A filter drawer, a cooling fan, a camera adapter and a CG-5 dovetail. Ready to image, straight out of the box.
1.25″ and 2″ filters. Without slowing you down.
The built-in filter drawer accepts both 1.25″ and 2″ filters. A removable 2″ clear optical window ships as standard. Unlike many fast astrographs, swapping in a filter adds no extra glass to the optical path, so f/2.2 performance is fully preserved.
Thermal equilibrium, fast.
The integrated 12V DC MagLev fan pulls air through mesh vents to rapidly cool the optical system to ambient temperature. Sharper stars and better images from the moment you start. The fan battery pack is included.
Plug a CMOS camera straight in.
The included M42 T-thread camera adapter attaches most popular astronomical CMOS cameras directly to the RASA 6 without extension tubes. The 42 mm clear aperture comfortably accommodates sensors up to 22 mm diagonal. Back focus with the included adapter is 17.5 mm.
Mount-ready, no adapters.
The CG-5 dovetail bar is compatible with a wide range of tracking mounts straight out of the box. No adapters, no Vixen-to-Losmandy conversions. Ready to image as soon as you saddle up. For maximum performance, add the optional Celestron Focus Motor for electronic focus control.
Results from the RASA 6.
Sample images taken with the RASA 6 and an IMX183C colour CMOS camera at f/2.2.
Highlights.
Everything that makes the RASA 6 the most portable serious astrograph in its class.
152 mm (5.98″) aperture, 335 mm focal length, f/2.2 prime focus
Patented Rowe-Ackermann Schmidt prime-focus astrograph optical design
StarBright XLT multi-layer coatings on every refractive and reflective surface
91% off-axis illumination at 8 mm and 472× light-gathering vs the eye
Useable field of 3.76° for sensors up to 22 mm diagonal
Built-in 1.25″ / 2″ filter drawer with included clear optical window
Integrated 12 V DC MagLev cooling fan with battery pack
3.8 kg optical tube with CG-5 dovetail for fast mount setup
Celestron RASA 6.
Complete technical data for your imaging setup planning.
| Optical Tube | |
| Optical design | Rowe-Ackermann Schmidt Astrograph |
| Aperture | 152 mm (5.98″) |
| Focal length | 335 mm (13.18″) |
| Focal ratio | f/2.2 |
| Optical coatings | StarBright XLT (all refractive and reflective surfaces) |
| Tube material | Aluminium |
| Tube length | 609.6 mm (24″) |
| Tube diameter | 177.8 mm (7″) |
| Weight | 3.8 kg (8.4 lb) |
| Dovetail | CG-5 dovetail bar |
| Focuser | Standard Schmidt-Cassegrain focuser |
| Optical Performance | |
| Central obstruction | 77 mm (3.03″) - 46% of aperture diameter |
| Light-gathering power | 472× vs the human eye |
| Resolution (Rayleigh) | 0.91 arc seconds |
| Resolution (Dawes) | 0.76 arc seconds |
| Spot size | < 1.5 μm RMS across the full image circle |
| Off-axis illumination | 91% at 8 mm (0.31″) off-axis |
| Wavelength range | 400–700 nm |
| Field of View & Camera Interface | |
| Image circle | 16 mm (0.63″) Ø, 2.74° |
| Useable field | 22 mm (0.86″) Ø, 3.76° (minimal performance loss at edge) |
| Camera mounting threads | M42 |
| Back focus (with adapter) | 17.5 mm (0.69″) |
| Filter System | |
| Filter drawer | Accepts 2″ format filters, includes 1.25″ adapter |
| Clear filter included | 2″ AR-coated optical window, 2 mm glass |
| Cooling & Electronics | |
| Cooling fan | 12 V DC MagLev |
| Fan power | Fan battery pack (included) |
| In the Box | |
| Included items | M42 (42 mm T-thread) camera adapter, fan battery pack, filter drawer with 2″ clear filter |
Professional optics. Portable by design.
The same prime-focus optical technology trusted by defence contractors and professional researchers, now in a grab-and-go package built for serious Australian astrophotographers. Backed by Bintel’s 40 years of expert optics support.
