- Rowe-Ackermann Schmidt Optical Design – 8” f/2.2 flat field imaging system with rare-earth glass for outstanding images free of optical defects like field curvature, coma, astigmatism and chromatic aberration across an entire APS-C sensor.
- Unlike the larger RASAs that work with DSLR and large CCD cameras, the 8” model was designed with color astronomical CMOS cameras, smaller CCD cameras, and mirrorless cameras in mind. The astrograph does not work with standard DSLR cameras.
- Ultra-Stable Focus System – precision linear ball bearing virtually eliminates image shift.
- Integrated air-cooling system –12V DC MagLev fan reduces cooldown time and provides optimal air flow while filtering out dust.
- Internal filter mount – seamlessly accommodates a Light Pollution Imaging Filter into the optical path.
- Performs over a wider spectral range than most telescopes, from 390-800 nm, so more of the light passing through the astrograph is in sharp focus.
- Advanced VX, the most compact and portable of Celestron’s German equatorial mounts, offers a maximum instrument capacity of 30 lb with the same rigidity as our larger mounts and minimal flexure.
- This mount offers every feature an astroimager wants: PEC, an autoguider port, the ability to image across the meridian, and more.
- Dual saddle plate is compatible with narrow CG-5 dovetails and wider CGE dovetail. Also compatible with Vixen format dovetails longer than 100mm, but not compatible with Losmandy D format plates.
- Accessories included: M42 camera adapter, C-thread camera adapter, and fan battery pack.
This kit combines the 8” Rowe-Ackermann Schmidt Astrograph (RASA) with the strong-yet-portable Advanced VX (AVX) German equatorial mount. Simply add a mirrorless camera and this package offers everything you need to take spectacular images of wide-field deep sky objects.
RASA Performance Made for Everyone
Capture spectacular wide-field deep sky images in seconds with Celestron’s portable astrograph, the 8” Rowe-Ackermann Schmidt Astrograph (RASA). This incredibly fast f/2.0 system is the perfect companion to today’s color astronomical CMOS cameras, smaller CCD cameras, and mirrorless cameras. Thanks to its fast focal ratio and patented optical design, you can produce sharp, detailed images and, in many cases, skip the autoguider completely. Weighing in at just 17 pounds, it’s easy to transport your 8” RASA to the most remote dark sky locations.
RASA Performance Made for Everyone
The 8” RASA is an imaging telescope that delivers a flat field without optical aberrations for razor sharp stars across a wide field of view. It can capture stunning deep-sky astronomical images without the challenges typically presented by longer focal length instruments at a fraction of the cost of those systems.
The latest addition to the RASA family, this 8” version is a much more portable and affordable version of the heralded RASA 11, which was introduced to much acclaim in 2014. With the 8” RASA joining the lineup, a wider range of astroimagers can enjoy the benefits of the RASA design. It has many of the same thoughtfully designed features as its “big brother” RASA 11, including the integrated air-cooling system, internal filter mount, and sturdy CGE dovetail mounting bar.
Purely designed for imaging, the 8” RASA 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.
Shorter Exposure Times and Virtual “Real-Time” Observing
Since it is an F/2.0 optical system, imagers can use shorter exposure times to capture detail in faint objects. When combined with sensitive cameras and the proper “live stacking” software, the 8” RASA can provide an almost real-time observing experience. View images on a computer instantly that are brighter and more detailed than can be seen in much bigger telescopes with the naked eye.
Because shorter exposure times are possible, your equatorial mount won’t need to accurately track over extended periods. The 8” RASA’s relatively short 400mm focal length also lessens equatorial tracking demands. In many cases, autoguiding will not be required. Weighing only 17 lb, this optical tube pairs perfectly with a wide variety of mounts.
Ultra-Stable Focus System
With the launch of the 8” RASA, Celestron unveiled a new focuser design that mitigates lateral movement of the primary mirror when focusing, slewing, or tracking with the astrograph. Focusing is easier, more accurate, and more stable than ever. The key to the Ultra-Stable Focus System is a precision linear ball bearing, which is tested during assembly to ensure optimal results.
Built for Today’s Latest Cameras
Unlike the larger RASAs that work with DSLR and large CCD cameras, the 8” model was designed with color astronomical CMOS cameras, smaller CCD cameras, and mirrorless cameras in mind. The telescope does not work with standard DSLR cameras. It is optimized for sensors with up to a 22mm diagonal, but performs well with sensors up to 32mm diagonal. The APS-C sized sensors used in many mirrorless cameras are a good choice. 42mm full frame sensors will also work, but performance will be poor at the edges of the sensor and field illumination will be reduced. Additionally, we do not recommend pairing RASA 8 with any camera body more than 4” in diameter. See the chart below to determine if your camera is compatible with RASA 8.
|Camera||Compatible with RASA 8?||Adapter required|
|Astronomical CMOS/CCD camera with C-mount||Yes||C-mount adapter (included)|
|Astronomical CMOS/CCD camera with M42-thread mount||Yes||M42 adapter (included) with M42 extension tubes (not included)|
|Astronomical CMOS/CCD camera with other mount||Yes||Custom camera adapter|
|Canon mirrorless with APS-C sensor||Yes||
|Sony mirrorless with APS-C sensor||Yes||
|Canon mirrorless with full frame (42mm) sensor||Yes, but not optimized across the full sensor||
|Sony mirrorless with full frame (42mm) sensor||Yes, but not optimized across the full sensor||
|OPTICAL TUBE INFO:|
|Optical Design||Rowe-Ackermann Schmidt Astrograph|
|Focal Length||400mm (15.74")|
|Central obstruction diameter||93mm (3.66") (46% of aperture diameter)|
|Light Gathering Power (Compared to human eye)||843x|
|Resolution (Rayleigh)||0.68 arc seconds|
|Resolution (Dawes)||0.57 arc seconds|
|Image Circle||22mm (.86") Ø, 3.15°|
|Useable field||32mm (1.26") Ø, 4.6°, only minimal performance loss at edge of FOV|
|Wavelength range||390 - 800 nm|
|Spot size||< 4.6 μm RMS across image circle|
|Optical Coatings||StarBright XLT|
|Off-axis Illumination||93% at 11mm (.43") off-axis|
|Optical Window||46mm (1.81") Ø|
|Back focus with included camera adapter||25mm (.98")|
|Back focus from top of threaded collar||29mm (1.14")|
|Optical Tube Length||628mm (24.7")|
|Optical Tube Diameter||235mm (9.3")|
|Focuser||Ultra-Stable Focusing System|
|Optical Tube Weight||17 lbs (7.7 kg)|
|Other Features||Air-cooling system, integrated filter mount|
|Included items||M42 camera adapter, C-thread camera adapter, fan battery pack|
|Dovetail||CGE Dovetail Bar|
|Mount Type||Computerized Equatorial|
|Instrument load capacity||30 lbs (13.6 kg)|
|Height adjustment range (includes mount and tripod)||1118mm - 1626mm (44" – 64")|
|Tripod Leg Diameter||50.8mm (2") Stainless Steel|
|Latitude adjustment range||7° - 77°|
|Mount Head Weight||17 lbs (7.71 kg)|
|Tripod Weight||18 lbs (8.16 kg)|
|Weight of Counterweights||1 x 12 lbs|
|Slew Speeds||9 slew speeds - max speed 4°/second|
|Tracking Rates||Sidereal, Solar and Lunar|
|Tracking Modes||EQ North & EQ South|
|Dovetail Compatibility||Dual saddle plates (CG-5 and CGE saddle)|
|Number of Auxiliary ports||3 Aux ports (1 hand control and 2 AUX ports for optional accessories)|
|USB Port||Yes, input on Hand Control|
|Power Requirements||12V DC 3.5A (tip positive)|
|Motor Drive||DC servo motors|
|Alignment Procedures||2-Star Align, 1-Star Align, Solar System Align, Last Alignment, Quick Align|
|Periodic Error Correction||Yes|
|Computerized Hand Control||NexStar+ hand control with LCD display, 19 fiber-optic backlit LED buttons|
|NexStar+ Database||40,000+ objects, 100 user defined programmable objects. Enhanced information on over 200 objects|
|Software||Celestron's Starry Night Special Edition Software, SkyPortal App|
|Total Kit Weight||47 lbs (21.31 kg)|
|Included Items||Advanced VX Equatorial Head| Tripod| Accessory Tray|1 x 12 lbs counterweight| NexStar+ Hand Control| DC Power Cable (plugs into cigarette lighter socket)|
Delivery Weight Package