Celestron 8" 203/400 Rowe-Ackermann Schmidt Astrograph (RASA 8) OTA (CGE Dovetail, SKU: 91073)

The Celestron Rowe-Ackermann Schmidt (RASA) 8" is a cutting-edge, high-speed (f/2.0) astrograph designed for capturing wide-field images using color CCD, CMOS, and small mirrorless cameras.

This astrograph features a patented optical system (patent US 2016/0299331 A1) that comprises a main mirror, a Schmidt corrector, and a group of four lenses made with rare earth metal-infused glass. This unique design allows for obtaining flat, aberration-free images, eliminating issues like coma, astigmatism, and chromatic aberrations. It also maintains a wide field of view and remarkable light-gathering capabilities, collecting nearly 850 times more light than the human eye. The lenses are coated with a multilayer StarBright XLT™ coating to minimize light reflections and enhance image contrast, while the main mirror is coated with reflective aluminum.

Unlike many popular telescopes that excel only in the visible light spectrum (400 - 700 nm), the Celestron Rowe-Ackermann Schmidt 8" astrograph offers an extended spectral range from 400 to 800 nm.

Encased in a sturdy aluminum tube, this astrograph features an active cooling system that significantly improves the temperature adaptation process, which can sometimes take several hours.

Please note that due to its design, the Celestron Rowe-Ackermann Schmidt 8" astrograph is exclusively intended for astrophotography and is not suitable for visual observations.

Key Features of the Celestron Rowe-Ackermann Schmidt 8" Astrograph:

• Rowe-Ackermann Schmidt optical system with StarBright XLT™ coating, delivering powerful light transmission and a distortion-free field of view that covers the entire APS-C sensor surface.

• Built-in holder for installing filters that reduce light pollution.

• Stabilized focusing system equipped with a linear ball bearing.

• Integrated cooling system that expedites the telescope's temperature adaptation process.

• CGE mounting rail for dovetail attachment.

Technical Specifications:

• Optical system: Rowe-Ackermann Schmidt

• Aperture: 203 mm / 8"

• Focal length: 400 mm

• Focal ratio: f/2.0

• Central obstruction (diameter/percentage of aperture): 93 mm / 46%

• Spectral range: 400 - 800 nm

• Rayleigh / Dawes resolution: 0.68" / 0.57"

• Optical window diameter: 46 mm

• Full illumination wheel diameter: 22 mm

• Full illumination circle field of view: 3.15°

• Useful field of view diameter: 32 mm

• Useful field of view: 4.6°

• Spot size: <4.6 µm RMS

• Off-axis illumination: 93% @ 11 mm

• Finder: Not included

• Focuser: Ultra-Stable Focusing System

• Back focus (with attached adapter): 25 mm

• Back focus (from the end of the thread): 29 mm

• Optical system coating: StarBright XLT™

• Main mirror cover: Aluminum

• Mounting for assembly: Dovetail CGE

• Tube material: Aluminum

• Cooling: Active, built-in

• Optical tube diameter: 235 mm

• Optical tube length: 628 mm

• Optical tube weight: 7.7 kg

Compatible Cameras for the Celestron Rowe-Ackermann Schmidt 8" Astrograph:

• CMOS / CCD astronomical cameras with C mount: Yes (with included adapter)

• CMOS / CCD astronomical cameras with M42 mount: Yes (with included adapter and separate adapter ring)

• CMOS / CCD astronomical cameras with other mounts: Yes (with appropriate separately available adapters)

• APS-C (Canon) mirrorless cameras: Yes (with a dedicated adapter)

• APS-C (Sony) mirrorless cameras: Yes (with a dedicated adapter)

• Full-frame mirrorless cameras (Canon): Yes (although optimal coverage of the entire frame may require a dedicated adapter)

• Full-frame mirrorless cameras (Sony): Yes (although optimal coverage of the entire frame may require a dedicated adapter)

• Digital SLR cameras - DSLR: No

Included Components:

• Celestron Rowe-Ackermann Schmidt Astrograph (RASA) 8"

• C-type adapter for mounting a CCD/CMOS camera

• M42 adapter for mounting a CCD/CMOS camera

• Battery compartment for the fan

Warranty:

The Celestron Rowe-Ackermann Schmidt 8" astrograph comes with a 24-month guarantee.