The RASA 11 is an F/2.2 astrograph with extremely fast photon capturing ability and a large full frame sensor format light footprint.  ASG Astronomy has worked extensively with these telescopes and offers a complete RASA 11 PRO or Standard system designed specifically for these telescopes.  Depending on your filter size choices, we can help get you 100% performance out of your RASA 11.

Today, with CCD sensor sizes as large as film or larger, the RASA 11 V2 offers a 43.3mm optimized image circle to capture pinpoint stars on the largest imaging chips. Optical performance for huge sensors with diagonals of up to 52mm wide is still excellent.

Combine this large image circle with a focal length of just 620mm and you have an instrument suitable for wide-field imaging, creating huge mosaics of the night sky, surveying, and even comet hunting.

Optical Performance
The RASA 11 V2 features optics with 4-element rare-earth glass for images free of false color and aberrations like coma and field curvature. The optical quality and spot size across the entire image circle are unprecedented for an astrograph in this price range—or even that of a much more expensive instrument. The design also provides minimal vignetting.

Advanced Features
RASA 11 V2 utilizes the new Ultra-Stable Focus System (USFS). At the heart of this system is a precision linear ball bearing. The bearing serves to minimize focus shift (unwanted lateral motion of the primary mirror during focusing which causes shifting of the image) and mirror flop (movement of the primary mirror when the telescope is pointing to different positions in the sky). The USFS is also compatible with the optional Celestron Focus Motor (#94155-A). The integrated 12V DC MagLev fan reduces cooldown time and provides optimal airflow through the dust filtered optical tube.

Product Specifications:

• Optical Design: Rowe-Ackermann Schmidt Astrograph
• Aperture: 279mm (11")
• Focal Length: 620mm (24.4")
• Focal Ratio: f/2.2
• Central obstruction diameter: 114mm (4.48") (41% of aperture diameter)
• Light Gathering Power (Compared to human eye): 1588x
• Resolution (Rayleigh): 0.49 arc seconds
• Resolution (Dawes): 0.41 arc seconds
• Image Circle: 43.3mm (1.7") Ø , 4.0°
• Useable field: 52mm (2.04") Ø , 4.8° only minimal performance loss at edge of FOV
• Wavelength range: 400 - 700 nm
• Spot size: < 4.4 μm RMS across FOV
• Optical Coatings: StarBright XLT
• Off-axis Illumination: 83% at 21mm (.82") off-axis
• Optical Window: 68mm (2.67") Ø
• Back focus with included camera adapter: 55mm (2.16")
• Back focus from top of threaded collar: 72.8mm (2.86")
• Optical Tube: Aluminum
• Optical Tube Length: 838.2mm (33")
• Optical Tube Diameter: 330.2mm (13")
• Focuser: Ultra-Stable Focus System
• Finderscope: Not included
• Optical Tube Weight: 43 lbs (19.5 kg)
• Other Features: Ventilation fan, dual dovetail mounting bars
• Included items:
  • 42mm (1.65") T-thread camera adapter
  • 48mm (1.89") camera adapter
  • Dust cover
  • Fan battery pack
• Dovetail: CGE Dovetail Bar