ASA 4" Cassegrain Field Flattener Corrector

  • Regular price Call For Price
  • ASA 4" Cassegrain Field Flattener Corrector

    • Sale
    • Call for Pricing
    • ITEM #

    • Will not ship until



    ASA 4" Cassegrain Field Flattener Corrector

    ASA 4" Cassegrain Field Flattener Corrector

    When using a classical Cassegrain telescope system, it should be used with a field flattening accessory to achieve a larger useful field of view. ASA provides this corrector lens, the Cassegrain Field Flattener Corrector - 4", which will improve your imaging performance considerably. This corrector lens will flatten the field and improve imaging over an 80mm diameter field on your classical Cassegrain scope.

    Given its large diameter, this ASA 4" Cassegrain Field Flattener Corrector will provide more than adequate corrected coverage for a Kodak KAF-16803 CCD Sensor (which is 36.8mm x 36.8mm in size)!

    Data obtained by ASA's physicist and designer, Philipp Keller shows that even at a field radius of 30mm, most of the energy contained within a well-focused star image falls within the Airy diffraction disk at a specific wavelength. The results are pinpoint stars from the edge of your CCD's field all the way to the center of the image. Your star images will thus be limited primarily by seeing conditions.

    The pertinent dimensions for the ASA Cassegrain Field Flattener Corrector - 4" are:

    • OD of mating surface, front cell barrel = 102mm (4")
    • OD of rear cell = 122mm
    • OAL = 47.61mm
    • ID of imager attachment, rear cell = 111.20mm
    • FFD = approximately 124mm (depends on telescope FL)
    • FFD (Flange focal distance) = Location of CCD plane behind flange
    • EFL (Effective focal length) = 500mm
    • Moves focus from original focal plane by only 1.15mm

    Additional Information


    Questions & Answers

    Have a Question?

    Be the first to ask a question about this.

    Ask a Question