Celestron RASA 6 Rowe-Ackermann Schmidt Astrograph – f/2.2 Imaging Power in a Compact Package
Celestron’s RASA 6 brings
the blazing speed and razor-sharp resolution of Rowe-Ackermann Schmidt
Astrograph optics to a compact, ultra-portable format. Weighing just 8.4
pounds and sporting a fast f/2.2 focal ratio, this 6" astrograph is a
deep-sky imaging powerhouse designed for on-the-go astrophotographers
and backyard imagers alike.
With its proven RASA
optical design, the 6" model delivers professional-grade performance in a
package small enough to travel with. Whether you're capturing wispy
nebulae from a dark-sky site or building a wide-field imaging setup in
your backyard, the RASA 6 makes it faster and easier to produce stunning
results—no matter where the night takes you.
Ultra-Fast f/2.2 Optics for Rapid Deep Sky Imaging
At the heart of the RASA 6
is Celestron’s proprietary f/2.2 optical system, engineered to
dramatically reduce exposure times. Compared to conventional telescopes,
this blazing-fast design allows you to collect more light in less time,
making it easier to image faint deep-sky targets like emission nebulae,
galaxies, and globular clusters—even under less-than-ideal conditions.
Shorter sub-exposures also
mean you can often ditch the autoguider altogether. With a capable
equatorial mount, the RASA 6 allows you to achieve crisp, detailed
results with minimal fuss. Live-stacking software can turn your setup
into a near real-time imaging machine—perfect for public outreach, EAA
(Electronically Assisted Astronomy), or simply enjoying your data as
it's captured.
Advanced Optics with Sub-Arcsecond Resolution
Despite its modest
aperture, the RASA 6 delivers performance that rivals—and often
exceeds—much larger and more expensive refractors. A key feature is its
ability to produce sub-arcsecond star images across a flat,
well-corrected field. When paired with a high-resolution CMOS camera and
good sky conditions, the RASA 6 can reveal intricate structures within
galaxies and diffuse nebulae, offering a level of detail that belies its
size.
The optical design
accommodates sensors up to 22mm diagonal, making it an ideal match for
most popular one-shot-color and mono astro cameras. The result is a
generous 3.8° field of view—perfect for framing large targets like the
North America Nebula, the California Nebula, the Heart and Soul, or even
sprawling star fields along the Milky Way.
Trusted by the Pros—Now in Your Hands
Originally introduced in
2014, the Rowe-Ackermann Schmidt Astrograph line has become a go-to tool
for satellite tracking, near-Earth object detection, and advanced
astroimaging by professionals and government agencies alike. The RASA 6
continues this legacy by offering the same optical excellence in a
format and price point accessible to amateur astronomers.
This isn’t just a fast
telescope—it’s a serious scientific instrument capable of producing
observatory-quality results, whether you're imaging for art, science, or
both.
Precision Engineering, Premium Coatings
The RASA 6 employs a
sophisticated optical layout including a Schmidt corrector plate,
high-precision spherical primary mirror, and a rare-earth glass
three-element lens group—all optimized for pinpoint star images and
flat-field performance.
Celestron's StarBright XLT
coatings are applied to all optical surfaces, maximizing light
throughput and enhancing image contrast. These coatings ensure you
capture the most light possible across the visual and near-infrared
spectrum, preserving subtle structures and delicate gradients in your
final images.
Built-In Flexibility and Smart Features
Celestron didn’t just
design a telescope—they engineered a complete imaging platform. The RASA
6 comes loaded with features that make imaging easier, cleaner, and
more reliable.
-
Filter Drawer System:
Accepts 1.25" and 2" filters and includes a removable 2" clear optical
window. Easily swap filters without disrupting your setup or adding
optical path errors.
-
Cooling Fan:
A quiet 12V MagLev fan brings the system down to ambient temperature
quickly while minimizing dust intake—ideal for night-to-night thermal
stability.
-
Camera Adapter Included: The M42-threaded adapter offers broad compatibility with many popular astronomy cameras and accessories.
-
CG-5 Dovetail Bar: Mounts easily to any standard Vixen-style saddle, ensuring compatibility with most equatorial mounts on the market.
Recommended Accessories
To get the most out of your RASA 6, consider pairing it with these Celestron accessories (sold separately):
-
Celestron Focus Motor: Enables remote, computer-controlled focusing with pinpoint precision.
-
6” Dew Shield or Dew Ring: Prevents moisture build-up on the corrector plate during long imaging sessions.
-
RASA 6 Padded Carry Bag: A dedicated, form-fitting soft case to protect your scope during travel and storage.
Performance That Outpaces Refractors
In terms of light grasp,
focal speed, and resolution per dollar, the RASA 6 is in a class of its
own. Compared to similarly priced refractors—many of which top out at
f/5 to f/7 and require expensive flatteners—the RASA 6 offers greater
sensitivity, faster results, and superior imaging potential for
wide-field deep-sky work.
If you're looking for a
second scope to complement your long focal length rig, or if you're
ready to jump into astrophotography with a system that delivers
breathtaking results from day one, the RASA 6 should be at the top of
your list.
In Summary
The Celestron RASA 6 Rowe-Ackermann Schmidt Astrograph
is the ideal fusion of speed, performance, and portability. Its
ultra-fast f/2.2 optics make deep-sky imaging faster and more
accessible, while its compact footprint and smart design features make
it easy to transport, set up, and adapt to your imaging workflow.
Whether you're a seasoned
astrophotographer looking for a wide-field solution or a beginner ready
to capture stunning deep-space images without long hours of tracking,
the RASA 6 opens the door to a universe of creative potential.
Tech Details:
Optical Tube Info: |
|
Optical Design: |
Rowe-Ackermann Schmidt Astrograph |
Aperture: |
152mm (5.98") |
Focal Length: |
335mm (13.18") |
Focal Ratio: |
f/2.2 |
Central obstruction diameter: |
77mm (3.03") (46% of aperture diameter) |
Light Gathering Power (Compared to human eye): |
472x |
Resolution (Rayleigh): |
0.91 arc seconds |
Resolution (Dawes): |
0.76 arc seconds |
Image Circle: |
16mm (0.63") Ø, 2.74° |
Useable field: |
22mm (0.86") Ø, 3.76°, only minimal performance loss at edge of FOV |
Wavelength range: |
400 - 700 nm |
Spot size: |
< 1.5 µm RMS across image circle |
Optical Coatings: |
StarBright XLT |
Off-axis Illumination: |
91% at 8mm (0.31") off-axis |
Back focus with included camera adapter: |
17.5mm (0.69") |
Optical Tube: |
Aluminum |
Optical Tube Length: |
609.6mm (24") |
Optical Tube Diameter: |
177.8mm (7") |
Focuser: |
Standard Schmidt-Cassegrain focuser |
Finderscope: |
Not included |
Optical Tube Weight: |
8.4 lbs (3.8 kg) |
Other Features: |
Air-cooling system, integrated filter mount |
Included items: |
42mm (1.65") T-thread camera adapter Fan battery pack Filter drawer with 2" clear filter |
Dovetail: |
CG-5 Dovetail Bar |
Filter Drawer: |
Accept 2" format filters, includes 1.25" filter adapter |
Clear Filter: |
2" filter, removable, AR coatings, 2mm glass thickness |
Cooling Fan: |
12V DC, MagLev |
Camera Mounting Threads: |
M42 |