Orion - 6 inch f/9 Ritchey Cretien Optical Tube Assembly

• Ritchey-Chretien optical design produces superb flat-field, coma-free images that are superior to those achievable with conventional reflector or Schmidt-Cassegrain telescopes
• The most compact Ritchey-Chretien astrograph available, at a breakthrough low price of less than $800! Until now, RCs typically cost upwards of $10,000
• Ideal for use with StarShoot-type CCD cameras and DSLRs for deep-sky and solar system astrophotography; provides a wide, fully illuminated field and pinpoint star clarity out to the edge of the camera
• Optical tube has eight computer-positioned baffles to ensure maximum contrast; primary mirror tube has four internal baffles; secondary mirror light shield has internal glare thread baffle
• Compact, lightweight optical tube can be easily accommodated on medium-sized equatorial mounts

If you were asked to describe the ideal telescope for amateur astrophotography, one that offered unparalleled performance wrapped in a compact design at an affordable price, your description would likely match our new 6" f/9 Ritchey-Chretien Astrograph. As a leading supplier of affordable imaging equipment and solutions for amateur astronomers, Orion is proud to introduce this highly regarded telescope design used by advanced astrophotographers and professional observatories worldwide - and even by the Hubble Space Telescope!

Previously available only in larger apertures that cost thousands more, the outstanding optical design of the Orion 6" f/9 Ritchey-Chretien Astrograph will allow you to capture spectacular, detailed images of deep-sky objects like never before. In contrast to conventional Newtonian reflector and Schmidt-Cassegrain systems that are susceptible to coma away from the center of the field, the Ritchey-Chretien utilizes hyperbolic primary and secondary mirrors to achieve superb flat-field images that are truly coma-free. In our 6" model, the mirrors are made of BK-7 optical glass with enhanced aluminum 94% - 96% reflectivity coatings, to provide diffraction-limited performance. Since there are no lenses involved, images are also free from chromatic aberration, which affects all but the finest, most expensive apochromatic refractors.

The Orion 6" Ritchey-Chretien Astrograph is ideal for use with small-format CCD cameras like our StarShoot line, as well as DSLR cameras, for deep-sky and solar system astrophotography. The telescope's wide, fully illuminated flat field produces pinpoint star clarity all the way to the edge of the camera's sensor.

The Orion 6" Ritchey-Chretien Astrograph features a machined, dual-speed (10:1) Crayford-style focuser with an engraved millimeter scale on the drawtube. One 2-inch and two 1-inch extension rings are included for adjusting the focus position for various cameras.

The secondary mirror is precisely center-marked to facilitate collimation. The 19-inch enameled steel optical tube weighs only 12.3 lbs. and features a dovetail mounting bar underneath, for trouble-free setup on medium or large-sized Orion equatorial mounts. The inside of the optical tube is fortified with eight computer-positioned light baffles, and the primary mirror baffle tube and secondary mirror light shield are also highly baffled to ensure maximum image contrast.

Without a doubt, our 6" Ritchey-Chretien Astrograph brings advanced astrophotography performance into the realm of affordability for most amateur astronomers. More affordable than comparably sized apochromatic refractors and without the coma that afflicts Newtonian reflectors, the Orion 6" f/9 Ritchey-Chretien Astrograph Telescope will take your astrophotography to new heights! One-year limited warranty.

Product Specifications:

Use Astronomy & terrestrial

User level Advanced

Optical design Ritchey-Chretien

Optical diameter 152mm

Focal length 1370mm

Focal ratio f/9.0

Optics type Hyperbolic

Resolving power 0.76arc*sec

Lowest useful magnification 22x

Highest useful magnification 300x

Limiting stellar magnitude 13.6

Optical quality Diffraction limited

Finder scope None

Focuser 2" Crayford

Secondary mirror obstruction 76mm

Secondary mirror obstruction by diameter 50%

Secondary mirror obstruction by area 25%

Mount style Optical Tube without Mount

Astro-imaging capability Lunar, planetary & long exposure

Tube material Aluminum

Length of optical tube 19.1 in.

Weight, optical tube 12.3 lbs.

Additional included accessories Two 1" and one 2" removable extension tubes Warranty One year

Included Items:

One two inch long extension ring

Two one inch long extension rings

One 1.25 inch eyepiece adapter insert

Starry Night Special Edition Software