Used Astro-Tech AT6RC - 6" f/9 Ritchey-Chretien - UT-12067 - SOLD

ITEM #
UT-12067
  • Sale
  • $269.00
  • Regular price $399.00
  • Used Astro-Tech AT6RC - 6" f/9 Ritchey-Chretien - UT-12067 - SOLD

    • Sale
    • $269.00
    • Regular price $399.00
    • ITEM #
      UT-12067

    0
    Already have gear? Trade it in for cash or new equipment.
    • This is a used telescope in very good condition*

    Used Astro-Tech AT6RC - 6" f/9 Ritchey-Chretien - UT-12067 - SOLD

    Astronomy Technologies - AstroTech AT6RC 6" f/9 Ritchey-Chretien Astrograph


    The Astro-Tech AT6RC is a truly affordable Ritchey-Chretien coma-free astrographic imaging system. The concept of a small and affordable 6" R-C originated with Astro-Tech, and the AT6RC was designed and developed specifically to Astro-Tech’s specifications from the very start to be the first 6" true Ritchey-Chretien made.



    The Ritchey-Chretien optical design is used in virtually every recent large mega-million dollar professional observatory including the Hubble Space Telescope. The more affordable true coma-free Ritchey-Chretien optical systems made for schools and individuals by commercial R-C manufacturers typically come only in large apertures and start at well over $10,000. Their size and cost used to put them out of the reach of most amateur astronomers. 


    The Astro-Tech AT6RC makes coma-free Ritchey-Chretien optics available at a price within reach and reason for nearly everyone. Designed for imaging, the Astro-Tech AT6RC provides the wide coma-free photographic field that astrophotographers crave, but can’t get from conventional reflectors and Schmidt-Cassegrains. The AT6RC can be used with webcams, Deep Sky Imager-type cameras, and DSLRs. Featuring a true Ritchey-Chr??tien optical system, the economical 6"Astro-Tech R-C makes you wonder just what those $10,000+ R-Cs have that makes them cost so much.




    The compact size and light weight of the AT6RC makes it easy for you to mount it on any mid-range equatorial mount by itself or piggyback it on an existing larger scope for imaging. Its 6" aperture, 1370mm focal length, f/9 focal ratio hyperbolic mirror optics are made of BK-7 optical glass. Eight contrast-enhancing glare-stop baffles in the optical tube, multiple glare-stop microbaffles in the secondary mirror light shield, and four baffles in the primary mirror baffle tube provide truly dark sky backgrounds during imaging.



    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. And, unlike complicated R-C designs that use motors to move the secondary mirror to focus, the AT6RC secondary mirror is fixed and focusing is done externally by a 2"  dual-speed Crayford focuser. Its 10:1 reduction gear microfine focusing provides exceptionally precise image control during critical CCD imaging.



    Focuser drawtube travel is 34mm. Two extension tubes are provided to let you change the position of the focuser relative to the rear cell. This lets you accommodate the varying back-focus requirements of webcam/Deep Sky Imager-type cameras versus that of DSLR-type cameras. Both 2" and 1.25" accessory holders with non-marring compression rings are provided to hold 2" and 1.25" imaging accessories in place.



    A Vixen-style dovetail bar runs the length of the underside of the optical tube. The dovetail can be removed, if desired, so the AT6RC can be installed in optional user-supplied mounting rings for piggyback mounting on a larger scope. A Vixen-style finderscope bracket dovetail base is installed on the upper left side of the optical tube. It can easily be removed if not needed. It will accept Vixen-style finderscope brackets as well as red dot-type finders.



    Astronomy Technologies - AstroTech AT6RC 6" f/9 Ritchey-Chrtien Astrograph Features


    • Hyperboloid primary mirror: Made of BK-7 optical glass. Polished to diffraction-limited 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.



    • Hyperboloid secondary mirror: Made of BK-7 optical glass. Polished to diffraction-limited 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.



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



    • Focuser travel: Focuser drawtube travel is 34mm. Two extension tubes are provided to let you change the position of the focuser relative to the rear cell. This lets you accommodate the varying back-focus requirements of imaging with a webcam/Deep Sky Imager-type camera versus imaging with a DSLR-type camera. Optional Astro-Tech 2" compression ring extension tubes are also available to fine-tune the back focus as needed. While it is possible to use SBIG ST-7/8/9/10/2000-type CCD cameras with the AT6RC, these cameras are generally not recommended. The weight of an SBIG camera and the color filter wheel typically used with it may cause the focuser drawtube to tilt slightly when fully extended, affecting the focus.



    • Compression ring accessory holders: The focuser drawtube ends in a 2" accessory 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.

      Specifications

      ConditionVery good
      ManufacturerAstrotech
      Warranty90 Day
    • Astrotech 6" RC optical tube
    • V size dovetail bar
    • 2" Crayford style focuser
    • 50mm extension tube
    • * Does not include finder, diagonal, eyepiece or 25mm extension. Also, there are some small nicks on white paint *

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