ASA 0.77X Schmidt-Cassegrain Reducer Corrector - 2"

  • Regular price Call For Price
  • ASA 0.77X Schmidt-Cassegrain Reducer Corrector - 2"

    • Sale
    • Call for Pricing
    • ITEM #

    • Will not ship until



    ASA 0.77X Schmidt-Cassegrain Reducer Corrector - 2"

    ASA 0.77X Schmidt-Cassegrain Reducer Corrector - 2"

    The ASA 0.77X Schmidt-Cassegrain Reducer Corrector - 2" could improve your images from your fast Schmidt-Cass telescope, by eliminating both coma and field curvature problems!

    This coma corrector fits into a standard 2" eyepiece barrel and it's optimized for CCD arrays which will fit within a circle of diameter 22mm or less. This includes (but is not limited to) the Kodak 8300 sensor format. This corrector can be used with a somewhat larger circular coverage, however there will be some minor loss of performance, and some vignetting at the edges. Note: It is not suitable for use with the Meade ACF telescopes.

    Without a good corrector, a Schmidt-Cassegrain Telescope will show substantial image errors. The most prominent for a Schmidt-Cass scope will be coma and curvature of field! Optimized for a bandwidth of 400nm to >700nm, and every lens used in the corrector is measured to verify its surface radius & thickness, before it is used in a system. The ASA 0.77X Schmidt-Cassegrain Reducer Corrector - 2" not only reduces the outer axial image errors (coma) but is also able to correct chromatic aberration introduced by the Schmidt plate.

    The results are pinpoint stars from the side all the way into the center of the image. The reducer will correct the focal length down by a factor of 0.77X. It's perfectly suitable for imaging performance on an APS-C format sized CCD chip, covering a major portion of the chip, with some vignetting at the longer dimension. This corrector uses three lenses. Designed by ASA physicist Philipp Keller.

    The pertinent dimensions for the 0.77X Schmidt-Cassegrain Reducer Corrector - 2" by ASA are:

    • OD of barrel = 50.80mm
    • No rear flange is used.
    • OAL (includes threads) = 39.09mm
    • Thread size = M48 x 0.75 x 3.50mm length
    • FFD = 97.50mm
    • FFD (Flange focal distance) = Location of CCD plane behind flange
    • Internal (female) threads for filter = M48 x 0.75

    The back focus will easily allow for using an off-axis guider. Suitable for use with many Celestron or Meade Schmidt-Cass telescopes.(Not for use with the Meade ACF telescopes.)

    ASA Products are priced and shipped from Austria. Prices may vary without notice as the currency exchange rate for the EURO and USD fluctuates slightly. Shipping estimates and most current pricing will be provided for you at the time of order.

    This item has product number: A2-2SCKORR.

    Additional Information


    Questions & Answers

    Ask a Question
    • Does this corrector work in a Meade LX200 10" native f/6.3 focal ratio?

      Technically, yes, but it will not achieve the same performance as the f/6.3 version of the LX200 10" has a totally different amount of coma and field curvature. Much like you could stack an f/6.3 reducer on an f/6.3 scope to go down to ~f/4, but the perf