Celestron 8" Rowe Ackerman OTA

CELESTRON SKU: 91073

$2,079.00

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These astro-images were captured with this scope by Land Sea & Sky ProStaffer Dustin!  With this unique scope, you can capture spectacular wide-field deep sky images in seconds. This incredibly fast f/2.0 system pairs easily with today’s color astronomical CMOS cameras, smaller CCD cameras, and mirrorless cameras. With its fast focal ratio and patented optical design, you can produce sharp, detailed images and, in many cases, skip the autoguider completely. Weighing in at just 17 pounds, it’s easy to transport your 8” RASA to the most remote dark sky locations.

 

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. It can capture stunning deep-sky astronomical images without the challenges typically presented by longer focal length instruments at a fraction of the cost of those systems.

 

Purely designed for imaging, the 8” RASA cannot be used visually. The prime focus focal plane is located at the front of the optical system, so it cannot accommodate a traditional eyepiece.

 

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. View images on a computer instantly that are brighter and more detailed than can be seen in much bigger telescopes with the naked eye.

 

Because shorter exposure times are possible, your equatorial mount won’t need to accurately track over extended periods. The 8” RASA’s relatively short 400mm focal length also lessens equatorial tracking demands. In many cases, autoguiding will not be required. Weighing only 17 lb, this optical tube pairs perfectly with a wide variety of mounts.

 

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.

 

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. The APS-C sized sensors used in many mirrorless cameras are a good choice. 42mm full frame sensors will also work, but performance will be poor at the edges of the sensor and field illumination will be reduced. Additionally, we do not recommend pairing RASA 8 with any camera body more than 4” in diameter. See the chart below to determine if your camera is compatible with RASA 8.

 

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