8” ROWE-ACKERMANN SCHMIDT ASTROGRAPH (RASA 8) OPTICAL TUBE ASSEMBLY (CGE DOVETAIL) - SKU# 91073 - In Stock Now

by Celestron
Save 39%
$2,939.95
$1,799.00
  • 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

Canon mirrorless adapter

(sold separately)

Sony mirrorless with APS-C sensor Yes

Sony mirrorless adapter

(sold separately)

Canon mirrorless with full frame (42mm) sensor Yes, but not optimized across the full sensor

Canon mirrorless adapter

(sold separately)

Sony mirrorless with full frame (42mm) sensor Yes, but not optimized across the full sensor

Sony mirrorless adapter

(sold separately)

DSLR No --

 

OPTICAL TUBE INFO:
Optical Design: Rowe-Ackermann Schmidt Astrograph
Aperture: 203mm (8")
Focal Length: 400mm (15.74")
Focal Ratio: f/2.0
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: Aluminum
Optical Tube Length: 628mm (24.7") length | 235mm (9.3") diameter
Focuser: Ultra-Stable Focusing System
Finderscope: Not included
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
Solar Warning
  • Never look directly at the Sun with the naked eye or with an optic (unless you have the proper solar filter). Permanent and irreversible eye damage may result.
  • Never use your optic to project an image of the Sun onto any surface. Internal heat build-up can damage the optic and any accessories attached to it.
  • Never leave your optic unsupervised. Make sure an adult who is familiar with the correct operating procedures is with your optic at all times, especially when children are present.

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