Capture spectacular wide-field deep sky images in seconds with Celestron’s 8” Rowe-Ackermann Schmidt Astrograph (RASA) portable astrograph mounted on Celestron’s state-of-the-art CGX equatorial mount- a perfect astroimaging combination!
The RASA 8″ is the latest additional to the Celestron RASA family. This 8” version is a much more portable and affordable version of the much heralded RASA 11″ model, which was introduced to the world to much acclaim in 2014. This was followed in 2017 with the gigantic RASA 14″/36cm. With the 8” RASA joining the lineup, a wider range of astroimagers can enjoy the benefits of the patented RASA design. It has many of the same thoughtfully designed features as the RASA 11, including the integrated air-cooling system, internal filter mount, and sturdy CGE dovetail mounting bar.
This incredibly fast f/2.0 system is the perfect companion to today’s colour 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 using an autoguider completely. Weighing in at just 7.7kg (17lbs), 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. 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. Since 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 is unveiling 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 two sets of precision bearings that are precisely aligned and tested during assembly to ensure optimal results.
The Celestron CGX Equatorial mount has been designed from the ground up to provide a solid and accurate platform for your telescope for both visual and astro-imaging requirements. The mount has a number of new and innovative features including a lower profile EQ head, which provides a more compact and stable mount; a better drive system; home and limit optical sensors with internal hard stops making it more remote operation-friendly; internal cable management.
In addition Celestron have made mechanical and ergonomic improvements too. These include conveniently located mount carrying handles to make transport and mounting (and removing) the mount on/off the tripod easier. There are also large latitude and dovetail clamp adjustment knobs to make the CGX easier to set up with your telescope.
The mount can be controlled with software developed in conjunction with PlaneWave Instruments – called CPWI – and is supplied free with the mount. CPWI uses advance PointXP mount modelling that allows you to add 100+ points to an alignment model for the mount set up, for the most accurate pointing and tracking possible for your Celestron telescope. The software also features an All-Star Polar Alignment routine, motor focus control and plate solving.
|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||Computerised Equatorial|
|Instrument load capacity||55 lbs (25 kg)|
|Height adjustment range (includes mount and tripod)||1200.15mm – 1968.5mm (47.25″ – 77.5″)|
|Tripod Leg Diameter||50.8mm (2″) Steel tripod with graduated markings on lower section|
|Latitude adjustment range||3° – 65°|
|Mount Head Weight||44 lbs (20 kg)|
|Tripod Weight||19.2 lbs (8.7 kg)|
|Weight of Counterweights||2 x 11 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 (Vixen and CGE saddle)|
|Number of Auxiliary ports||2 Aux ports (Hand Control can use either Aux port)|
|USB Port||Yes, input for Mount and Hand Control|
|Power Requirements||12V DC, 4 amps|
|Motor Drive||DC servo motors|
|Alignment Procedures||2-Star Align, 1-Star Align, Solar System Align, Last Alignment, Quick Align|
|Periodic Error Correction||Yes|
|Computerised Hand Control||2 line x 18 character backlit Liquid Crystal Display, 19 LED backlit buttons, USB 2.0 port for PC connection|
|NexStar+ Database||40,000+ objects, 100 user defined programmable objects. Enhanced information on over 200 objects|
|Software||PWI Telescope Control Software, Celestron’s Starry Night Special Edition Software, SkyPortal App|
|Total Kit Weight||124.2 lbs (56.3 kg)|
|Included Items||CGX Equatorial Head | CGX Tripod | Accessory Tray | 2 x 11 lbs counterweights | NexStar+ Hand Control | 8mm Allen Wrench | 12V DC Power Cable | Hand Control Holster|