Great Red Spot Astronomy Products

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Astro-Tech
Ritchey-Chrétien astrographs
Pre-Order yours today.
At this price they will be hard to get!

True Ritchey-Chrétien telescopes typically start at well over $10,000, putting them out of the reach of most astrophotographers. At least, true R-Cs used to start at $10,000 and up.

Introducing the Astro-Tech AT6RC, an incredibly affordable Ritchey-Chrétien astrograph that virtually all astrophotographers can afford!

The Astro-Tech AT6RC makes the coma-free imaging of a true Ritchey-Chrétien optical system available to amateur astronomers using webcams, Deep Sky Imager-type cameras, and SBIG ST-7/8/9/10/2000-class CCD cameras. And it does it at a price less than that of even the least-expensive SBIG CCD camera. Featuring a true Ritchey-Chrétien optical system, this incredibly economical 6" Astro-Tech R-C makes you wonder just what those $10,000+ R-Cs have that makes them cost so much.

Designed strictly for exceptional imaging, the Astro-Tech AT6RC and AT8RC provides the wide coma-free photographic field that astrophotographers crave, but can’t get from conventional reflectors and Schmidt-Cassegrains. Likewise, as a pure two-mirror system, the AT6RC is totally free from the spurious color that affects the imaging of all but the most costly apochromatic refractors, and it does it with an 6" aperture that equals or exceeds the light gathering of most apo refractors.

If serious astrophotography is your goal, but the price of most true Ritchey-Chrétien optics has been keeping you from the optical design most modern professional observatories and the Hubble Space Telescope use for their imaging, your wait is over. The Astro-Tech AT6RC can bring the world of professional deep space imaging to your backyard observatory at a truly affordable price.

These Astrograph Optical Systems include. . .

• Optical design: true Ritchey-Chrétien Cassegrain-type two-mirror optics, with hyperbolic primary and secondary mirrors. For more details, click on the “optics" icon above.

• Aperture: 6", 1370mm focal length, f/9 focal ratio.

• Aperture: 8", 1928mm focal length, f/9 focal ratio.

• Primary mirror: Made of BK-7 optical glass. Polished to 1/12th wave or better surface accuracy. Unlike designs that move the primary mirror fore and aft in the optical tube to focus (which can lead to image shift as the mirror position changes) the AT6RC primary mirror is fixed to eliminate image shift and focus changes.

• Secondary mirror: Made of BK-7 optical glass. Polished to 1/12th wave or better surface accuracy. Mounted in a four-vane spider and fully collimatable using simple standard Schmidt-Cassegrain collimating techniques. Unlike complicated R-C designs that use motors to move the secondary mirror fore and aft to focus, the AT6RC secondary mirror is fixed and focusing is done externally.

• Enhanced aluminum optical coatings: Both primary and secondary mirrors have enhanced aluminum mirror coatings, overcoated with a protective layer of quartz for long life. Reflectivity is in the 96% range, the same as those $10,000+ R-C scopes.

• Optical tube on the AT6RC: Aluminum, with die-cast and machined aluminum front and rear cells.

• Optical tube on the AT8RC: Made of light weight/high strength woven carbon fiber-reinforced composite material with extremely low thermal expansion characteristics to reduce the possibility of temperature-related focus changes. Die-cast and machined aluminum front and rear cells. The carbon fiber tube is virtually indestructible. The use of a carbon fiber composite reduces the weight of the optical tube with no loss of strength or rigidity compared to an aluminum tube. Carbon fiber composites are so strong that the new $200,000,000 Boeing 787 Dreamliner passenger jet will use a wing and fuselage made entirely out of carbon fiber.
   

• Internal light baffles: Computer optimized primary and secondary baffling. Contrast-enhancing glare-stop baffles in the optical tube, with multiple glare-stop microbaffles in the secondary mirror light shield and primary mirror baffle tube to provide truly dark sky backgrounds during imaging.

• Dual-speed Crayford focuser on the AT6RC: The non-vignetting focuser has dual-speed focusing. There are two coarse focusing knobs. The right knob also has a smaller concentric knob with a 10:1 reduction gear microfine focusing ratio. This provides exceptionally precise image control during critical CCD imaging. All focus knobs are ribbed, so they are easy to operate, even while wearing gloves or mittens in cold weather.

• Dual-speed microfine Feather Touch Crayford focuser on the AT8RC: The precision-made non-vignetting focuser is a genuine Feather Touch from Starlight Instruments, a company known world-wide for making the finest and most reliable focusers available to the amateur astronomer. The focuser has dual-speed focusing. There are two coarse focusing knobs. The right knob also has a smaller concentric knob with a 10:1 reduction gear microfine focusing ratio. This provides exceptionally precise image control during critical 35mm or CCD imaging. All focus knobs are ribbed, so they are easy to operate, even while wearing gloves or mittens in cold weather. Multiple internal baffles in the focuser drawtube assure high contrast.
   

• Compression ring eyepiece holders: The focuser drawtube ends in a 2" eyepiece holder that uses a non-marring soft brass compression ring to hold 2" imaging accessories in place. The compression ring won’t scratch the barrel of your accessories as an ordinary thumbscrew can. Also supplied is a 1.25" accessory holder that slips into the 2" compression ring holder to let you use 1.25" imaging accessories. Like the 2" eyepiece holder on the eyepiece holder rotation mechanism, the 1.25" adapter also uses a non-marring soft brass compression ring.

• Mounting dovetail: removable Vixen-style dovetail bar running the length of the underside of the optical tube.

• Other accessories: A slip-on dust cap is standard.

Two year warranty: As an expression of the confidence Astronomy Technologies has in the quality of their products, the Astro-Tech AT6RC is protected by a two-year limited warranty against flaws in materials and workmanship (shipping case excluded).

The AT6RC Ritchey-Chrétien astrograph has:

• 6" f/9 true Ritchey-Chrétien hyperbolic mirror optical design
• 1/12th wave or better BK-7 mirrors
• enhanced aluminum optical coatings
• dual-speed Crayford focuser
• 2" and 1.25" compression ring eyepiece holders
• Vixen-style dovetail plate


The AT8RC Ritchey-Chrétien astrograph has:

• 8" f/9 true Ritchey-Chrétien hyperbolic mirror optical design
• low thermal expansion quartz primary and secondary mirrors
• 99% reflectivity non-tarnishing dielectric mirror coatings
• high strength/low thermal expansion carbon fiber optical tube
• genuine Feather Touch dual-speed Crayford focuser
• 2" and 1.25" compression ring eyepiece holders
• Losmandy-style “D-plate" dovetail

Pre-Order: New product; You may order now and reserve your unit today before they are gone. You can also call or e-mail us to be put on a waiting list at no charge as well.
Price $1295.00 6" f/9 Ritchey-Chrétien Astrograph

 

Pre-Order: New product; You may order now and reserve your unit today before they are gone. You can also call or e-mail us to be put on a waiting list at no charge as well.
Price $2995.00 8" f/9 Ritchey-Chrétien Astrograph