Advance notice Celestron RASA 6" - Rowe-Ackermann Schmidt Astrograph

Flat, distortion-free field of view, free from optical errors such as field curvature, coma, astigmatism, and chromatic aberration across the entire field up to a sensor diagonal of 16 mm.
Ultra-stable focusing system - six sealed precision ball bearings prevent image shift.
Integrated air cooling system - 12V DC MagLev fan with dust cover reduces cool-down time and ensures optimal airflow.
Internal filter drawer - seamlessly integrates an optional light pollution filter into the light path.
Extended field of view: Optimized for sensors with a diagonal of up to 16 mm, RASA 6 offers a generous 3.8° field of view, easily capturing large celestial objects.
The RASA 6 optics were first used in the Celestron Origin – Intelligent Home Observatory (#821880, €5299) and are now also available as a standalone telescope.

RASA 6" - Rowe-Ackermann Schmidt Astrograph

Celestron's portable astrograph, the 6" Rowe-Ackermann Schmidt Astrograph (RASA), can capture spectacular wide-angle deep-sky images in seconds. This incredibly fast f/2.2 system is the perfect telescope for modern astronomical CMOS color cameras and smaller CCD cameras.

Thanks to the large focal ratio and patented optical design, you can produce sharp, detailed images and, in many cases, eliminate the need for an autoguider altogether. Weighing just 3.8 kg (8.4 lbs), the 6" RASA is easy to transport to even the most remote locations.
RASA Performance for Everyone

The 6" RASA is a telescope designed purely for photography, providing a flat field of view free of optical aberrations, revealing extremely sharp stars across a wide field of view. It enables astronomical images with impressive "depth" and avoids the problems typically associated with longer focal length (and slower focal ratio) instruments.

The latest addition to the RASA family, with a 6" aperture, is a much more portable and affordable version of the RASA 11, which was introduced to great acclaim in 2014. With the 6" RASA, the advantages of the RASA design are now available to a wider range of astrophotographers. It shares many features with its "big brother," the RASA 8, including the integrated cooling system, the StarBright XLT coating, and the robust CGE dovetail mount.

The 6" RASA is designed exclusively for photography and cannot be used for visual observation. The focal plane is located at the front of the optical system, so the telescope cannot accommodate a conventional eyepiece.
Shorter Exposure Times and Virtual "Real-Time" Observation

Because it's an f/2.2 optical system, astrophotographers can use shorter exposure times to capture details in faint objects. When combined with sensitive cameras and the right "live stacking" software, the 6" RASA also allows for near-live observations: you can instantly view and stack images on a computer, making them brighter and more detailed than with the naked eye—even compared to much larger telescopes!

Because shorter exposure times are possible, your mount doesn't need to perform high-precision tracking for extended periods. The short focal length of 335 mm of the 6" RASA further reduces tracking requirements. In many cases, autoguiding is not necessary. Weighing only 3.8 kg, this telescope is ideally suited to a wide range of commercially available mounts.

Ultra-stable focusing system

The RASA 6 also features the improved focusing mechanism, which reduces the play of the primary mirror when focusing, tilting, or tracking the astrograph. Focusing is easier, more accurate, and more stable than ever. The key to this ultra-stable focusing system are two sets of precision bearings, which are precisely aligned and tested during assembly to ensure optimal results.
Unique optical design

The patented RASA design (US 2016/0299331 A1) consists of a Schmidt-type plate, primary mirror, lens group, and optical window. The lens group consists of three elements and uses rare earth elements. The device is optimized for the spectral range of 400-700 nm. This allows more light from celestial objects to be collected and sharply imaged.

The RASA 6 features a built-in 2" clear glass filter. It can be replaced, for example, with a nebula filter of the same thickness without having to add additional glass to the focus path. This means that the focus position and optical performance remain unchanged even when using a filter.

For many optical systems, the use of an additional flat glass such as a filter makes no difference to image quality. However, for extremely fast systems like the RASA, this is different. Our developers have solved this problem by equipping the RASA with an optical window that can be removed and replaced with a filter. This ensures the highest image quality even when using a filter or if the camera has its own optical window. Celestron offers an anti-light pollution filter specifically designed for the 6" RASA that replaces the optical window.

All refractive optical surfaces are StarBright XLT coated, and the primary mirror has an enhanced aluminum coating. This ensures high transmission for the entire system. Compared to the HyperStar system for Schmidt-Cassegrains, the RASA 6 delivers better optical performance and superior illumination.
Advanced Features and Versatility

Designed with the modern astrophotographer in mind, the RASA 6 is equipped with numerous features that enhance usability and adaptability:

Built-in Filter System
The integrated filter drawer accommodates both 1.25" and 2" filters, giving you the flexibility to use various broad- and narrow-band filters. The removable 2" clear glass filter (i.e., the optical window) allows you to add optional filters if desired without introducing additional glass into the optical path, which could compromise performance at f/2.2.
Integrated Cooling System
A 12V MagLev fan draws air through mesh vents to quickly cool the system to ambient temperature, delivering the best images while keeping internal components dust-free.
M42 Camera Adapter
The included camera adapter for the RASA 6 features a standard M42 thread, making it easy to mount a wide variety of astronomical CMOS cameras.

Designed for the Most Modern Cameras

Unlike the larger RASAs, which are optimized for DSLRs and large CCD cameras, the 6" model is designed for astronomical CMOS cameras and smaller CCD cameras. The telescope does not work with standard DSLR cameras due to the available backfocus. It is optimized for sensors up to 16 mm diagonal and still offers good performance on sensors up to 22 mm diagonal (22 mm diagonal sensors also work well, but reduced field illumination in the corners should be expected). Furthermore, we do not recommend combining the RASA 6 with a camera body with a diameter larger than 75 mm.

To achieve the highest level of performance, we strongly recommend combining this telescope with the focus motor, the 6" aluminum dew shield, the 6" heater ring, and the 6" RASA bag (all sold separately). The focus motor allows you to achieve sharp, precise focus electronically using the same computer that controls your camera. The dew cap or dew heater helps you keep the optics clear during long periods of observation, especially in humid conditions. When not in use, you can store and transport your RASA in the protected, portable case. The 6" RASA offers the perfect blend of speed, precision, and portability. Its revolutionary optical design and robust mechanical properties allow you to image the night sky like never before. A portable astrograph that opens up a vast, limitless universe.

Technical Specifications
RASA 6" - Rowe-Ackermann Schmidt Astrograph
Product Specifications

Item Number
822255
EAN Code
4047825060471
Manufacturer
Celestron

Optics

Image Scale
16 mm (0.63")
Resolution (DAWES)
0.76 arcseconds
Resolution (RAYLEIGH)
0.91 arcseconds
Back Focus
17.5 mm from the included M42 camera adapter
Special Features
Air cooling system, integrated filter holder
Field of View
16 mm (0.63") Ø, 2.74°
Focal Length
335 mm (13")
Light gathering power (to the human eye)
472x
Usable field
16 mm (0.63") Ø, 2.74°; At 22 mm (0.86") diameter, 3.15° minimal power loss at the corner of the field of view
Obstruction
77 mm (3.03") (46% of aperture)
Optical Design
RASA
Optical Coating
Starbright XLT (Fully Multi-Coated)
Spot Size
< 1.5 μm RMS across the image circle
Telescope Series
RASA
Telescope Aperture
152 mm (6")
Tube Material
Aluminum
Tube Weight
3.8 kg (8.4 lbs)
Tube Size (max)
177.8 mm (7")
Tube Length
609.6 mm (24") Length | 177.8 mm (7") Diameter
Coating
StarBright XLT
Wavelength Range
400 - 700 nm
Focal Ratio
f/2.2

Accessories Included

Focuser
Ultra-stable focusing system
Includes accessories
M42 camera adapter, battery holder for fan, filter slider with 2" clear glass filter
Viewfinder
Not included