Celestron Rowe-Ackermann Schmidt (RASA) 11 "is a professional, ultra-fast (f / 2.2) astrograph designed for taking pictures in a wide field of view using CCD, CMOS and digital SLR cameras.

The optical system of this astrograph is a patented construction (patent US 2016/0299331 A1) consisting of a main mirror, a Schmidt corrector and a group of four lenses made of glass with an admixture of rare earth metals. The advantage of this solution is the possibility of obtaining a flat image without optical defects (coma, astigmatism and chromatic aberrations), while maintaining a wide field of view and a very large light (this instrument collects almost 1,600 times more ¶ light than the human eye). In order to minimize light reflections and to improve the contrast of the image obtained, the lenses were covered with a multilayer StarBright XLT ™ coating, while the main mirror was covered with a reflective layer made of aluminum.

The whole is closed in a durable, aluminum tube equipped with an active cooling system, which significantly improves the process of temperature adaptation, which sometimes takes several hours.

Attention! As the image is captured by a camera placed in the focus of the main mirror, this instrument can only be used in astrophotography. It is not suitable for visual observations.

The most important features of the Celestron Rowe-Ackermann Schmidt 11 "astrograph

• Rowe-Ackermann Schmidt optical system with StarBright XLT ™ coating, providing powerful light and aberration-free field of view covering the entire surface of the full-year sensor
• stabilized focusing system equipped with a linear ball bearing, compatible with the Celestron Focus Motor drive
• integrated cooling system accelerating the process of temperature adaptation of the telescope
• double dovetail CGE mounting rail

Technical specifications

• optical system: Rowe-Ackermann Schmidt
• aperture: 279 mm / 11 "
• focal length: 620 mm
• lighted: f / 2.2
• central obstruction (diameter / percentage of the aperture): 114 mm / 41%
• spectral range: 400 - 700 nm
• Rayleigh / Dawes resolution: 0.49 "/ 0.41"
• Diameter of the optical window: 68 mm
• diameter of full illumination wheel: 43.3 mm
• field of view circle of full illumination: 4 °
• useful field of view diameter: 52 mm
• useful field of view: 4.8 °
• spot size: <4.4 µm RMS
• off-axis illumination: 83% @ 21 mm
• finder: missing
• fokuser: Ultra-Stable Focusing System
• back focus (with attached adapter): 55 mm
• back focus (from the end of the thread): 72.8 mm
• type of optical system coating: StarBright XLT ™
• main mirror cover: aluminum
• mounting for assembly: dovetail CGE
• tube material: aluminum
• cooling: active, built-in, fan with magnetic suspension
• Diameter of the optical tube: 330.2 mm
• length of the optical tube: 838.2 mm
• weight of the optical tube: 19.5 kg

Cameras and cameras compatible with the Celestron Rowe-Ackermann Schmidt 11 "astrograph (If the camera's back focus is less than 55mm, it will be necessary to install the appropriate spacer rings):

• CMOS / CCD astronomical cameras with M42 mount: yes (through the included adapter)
• CMOS / CCD astronomical cameras with M48 mount: yes (through the included adapter)
• CMOS / CCD astronomical cameras with other mounts: yes (through appropriate adapters available separately)
• digital SLR cameras - DSLR: yes (through a separately available T-ring dedicated to a given photographic system)

Elements of the set

• Celestron Rowe-Ackermann Schmidt astrograph (RASA) 11 "
• M48 adapter for mounting a CCD / CMOS camera
• M42 adapter for mounting a CCD / CMOS camera
• telescope cover
• battery compartment for the fan

guarantee

24 months