8” ROWE-ACKERMANN SCHMIDT ASTROGRAPH (RASA 8) OPTICAL TUBE ASSEMBLY (CGE DOVETAIL) - SKU# 91073 - In Stock Now
- Flat field free of optical aberrations 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 telescope 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.
- CGE dovetail mounting rail.
- 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.
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.
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.
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.
Ultra-Stable Focus System
With the launch of the 8” RASA, Celestron is unveiled a 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.
|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") length | 235mm (9.3") diameter|
|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|