Celestron CGX 11" RASA (Rowe-Ackermann Schmidt Astrograph) - Discontinued

  • A 279 mm (11-inch) Aperture RASA Schmidt Astrograph.
  • A Wide-field at only f/2.2.
  • 43.4 mm image circle.
  • The CGX mount is quick and quiet.
  • Exposure times are greatly reduced.


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Celestron CGX 11" RASA (Rowe-Ackermann Schmidt Astrograph) - Discontinued

This Package Includes:

  • Celestron RASA 11-inch OTA.
  • M42 camera adapter.
  • C-thread camera adapter.
  • Fan battery pack.
  • CGX equatorial head.
  • CGX tripod and spreader/accessory tray.
  • (3x) 11-pound counterweights.
  • NexStar+ hand control and holster.
  • 8 mm Allen wrench.
  • 12V DC power cable.

The Rowe-Ackermann Schmidt Astrograph, known mainly as the Celestron RASA, became one of the best astrophotography telescopes the moment it was released. Since then, its popularity has only grown due to the incredibly fast optics for efficient imaging, absurdly clear optics from edge to edge of the aperture, and the fact that it's one of the most reasonably priced, professional-grade telescopes available. Any astrophotographer will say the same great things about the Celestron RASA astrograph telescope. Experience as close to perfection as you can get in a portable package with the RASA series telescopes.

Paired for Excellence with the Celestron CGX

The Celestron RASA 11-inch has been paired with the CGX equatorial mount to bring out the best in your astrophotography system. With a load capacity of 55-pounds, you can fully customize your RASA to be the ultimate imaging rig. This mount is also fully-equipped with some of the best astrophotography software available, like StarSense and CPWI to bring professional-grade performance to an amateur-friendly system.

Fast Optics for Short Exposures and "Real-Time" Observing

Use shorter exposure times to capture detail in faint objects with its f/2.2 optical system. When combined with sensitive cameras and the proper live-stacking software, the 11-inch RASA can provide an almost real-time observing experience. Instantly view images on a computer that are brighter and more detailed than what you would see with the naked eye in bigger telescopes.

Because shorter exposure times are possible, your equatorial mount won’t need to accurately track over extended periods. The 11-inch RASA's relatively short 400 mm focal length also lessens equatorial tracking demands. In many cases, autoguiding will not be required.  

Below you'll see an incredible image of the Rosette Nebula taken by Jason Guenzel using the Triad Ultra filter on the super-fast f/2.2 Celestron RASA telescope! 

Jason Guenzel Nebula with RASA and Triad Ultra

An Astrograph for Everyone

The 11-inch 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.

Focusing Made Easy

Focusing is easier, more accurate, and more stable with its new focuser design that mitigates lateral movement of the primary mirror when tracking with the astrograph, focusing, or slewing. Two sets of precision bearings are precisely aligned and tested during assembly to ensure optimal results.

Imaging in the Modern Age

Designed to pair with color astronomical CMOS cameras, smaller CCD cameras, and mirrorless cameras, it is optimized for sensors with up to a 22 mm diagonal. It can accept larger sensors (up to 32 mm diagonal), as well as APS-C sized sensors used in many mirrorless cameras.

Camera adapters, to connect C-mount cameras and cameras which mount with M42 threads are included.  

Please note: The 11-inch RASA will not work with standard DSLR + T-ring systems. OPT offers optional adapters to connect your 11-inch RASA to Sony, Canon, or other mirrorless cameras.

Unique Optical Design

RASA’s optical design is patented (US 2016/0299331 A1). The design consists of a Schmidt corrector, primary mirror, lens group, and optical window. The lens group contains 4 elements and utilizes rare-earth elements. Unlike many telescopes that only perform well over the visible spectrum (400 to 700 nm).

With many imaging systems, adding an extra piece of flat glass such as a filter does not change optical performance. However, that is not the case with super-fast optical systems like the RASA. The Celestron design engineers addressed this by designing the RASA with a removable optical window, so you can maintain peak optical performance if a filter is added or if a camera has its own optical window. Celestron offers a Light Pollution Imaging Filter designed specifically for the 11-inch RASA, which mounts in place of the optical window.

All refractive optical surfaces are coated with StarBright XLT coatings, while the primary mirror uses enhanced aluminum coatings. This maintains high light transmission through the entire optical system. When compared with Hyperstar SCT systems, the RASA 11 provides better optical performance and field illumination.

Highlighted Features of the Celestron RASA

  • Designed with a Schmidt corrector, primary mirror, lens group, and optical window.
  • A removable optical window, so you can maintain peak optical performance if a filter is added or if a camera has its own optical window.
  • Celestron offers a Light Pollution Imaging Filter designed for the 11-inch RASA, which mounts in place of the optical window.
  • All refractive optical surfaces are coated with StarBright XLT coatings, while the primary mirror uses enhanced aluminum coatings.

Included Technology

All-Star Polar Alignment

Get ready for a night of astroimaging with your mount faster than previously thought possible with All-Star Polar Alignment. This innovative software solves the time-consuming problem of trying to pinpoint the North Celestial Pole.

Compatible Technology


The new Lithium Phosphate (LiFePO4) battery chemistry has significant advantages over other battery chemistries, great for those Astronomers on the go.

Starsense Technology

Celestron’s patented StarSense Technology makes it easier than ever to locate objects in the night sky, even if you’ve never used a telescope before. Turn it on and push ‘Align.’ In about three minutes, you’re ready to observe!


WiFi technology encircles the globe in a web of connectivity, knowledge, and information. Now, Celestron is using that same technology to allow stargazers to connect to the night sky and enhance their experience of the cosmos in fun and unique ways.


Aperture279 mm (10.98")
Aperture279 mm (11")
Back Focus72.8mm
Camera/Eyepiece ConnectionM42x0.75
Camera/Eyepiece ConnectionMale T—Thread (M42x0.75)
Corrected Image Circle43.3mm
Dawes Limit0.42 arcseconds
Dew Shield Size279mm
Focal Length620 mm
Focal Ratiof/2.2
Free ShippingYes
Head DesignEquatorial
Highest Magnification558x
Instrument Capacity55 lbs
Latitude Range3 to 65 Degrees
Light Gathering Power1589x
Limiting Magnitude16
Mount Head Weight44 lbs
Optical DesignRASA
PortsAutoguide Port
PortsHand Controller
PortsUSB 2.0
Power Consumption12V 5A max
RMS Spot Size4.4 microns
Secondary Obstruction114mm
Slew Speed5 Degrees Per Second
Telescope ConnectionDual V Style and D Style
Tracking ModesEQ North
Tracking ModesEQ South
Tracking RatesLunar
Tracking RatesSidereal
Tube Diameter330mm
Tube Diameter838mm
Tube Length330mm
Tube Length838mm
Tube Weight43 lbs


  • Celestron's 279 mm (11-inch) RASA Schmidt astrograph.
  • Camera adapters: M48 and T-thread.
  • Celestron CGX mount.
  • Tripod: adjustable, 2-inch steel legs.
  • Hand controller: NexStar +.
  • (3x) Counterweights, 11-pounds each/ locking.
  • Spreader bar/accessory tray.
  • Focuser style: FeatherTouch/ two speed/ 2-inch/ 1:10 ratio.
  • 2 Year Manufacturer's Limited Warranty.


Customer Reviews
5 Based on 1 Reviews
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Robert O.
What a Beast!

This telescope is big and heavy. The CGX mount does a wonderful job handling heavy loads. After pointing it in the rough direction of North, and doing a simple two-star alignment, it was able to find any object in the sky accurately, and could track for 60 seconds. The next time I used it, I did a 6-star alignment and went through the ASPA procedure and was able to guide for 2 minutes with the RASA. I know I could go a lot longer than 2 minutes but any image coming out of the RASA after 2 minutes would be over-exposed. Definitely an excellent, solid mount with virtually no backlash or drift. As for the RASA, I was a little dismayed to see a small scratch on the corrector plate and another one on the primary mirror (how?) but other than that it really does perform! Most objects at zenith in a Bortle 3-4 sky will be well-exposed at 90 seconds before light pollution becomes overwhelming. The focusing is very precise and an electric focuser is almost a must. The focus locks work really well (keeps focus for several hours). I'd heavily recommend a heated dew shield and a laser/red dot sight for locating objects during alignment. The only real complaint I have is that taking darks, flats, and biases is a pain since the DSLR is in the front, but it should be much easier with a CCD/CMOS camera (which I plan on getting soon). Overall, this thing is a really nice toy.