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Gerd Neumann 10 L/mm Ronchi Eyepiece - 1.25"

SKU : GN-10-101-150

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Product Details

  • The 10 mm Ronchi Eyepiece - 1.25" by Gerd Neumann Jr:


    This Gerd Neumann Jr. 10 mm Ronchi Eyepiece accessory will help you to check the quality of nearly any telescope you come across in the future! While it is true that optical aberrations can be determined by the star test, this method requires steady air and an experienced observer. The Ronchi test is far less demanding: It works within medium air and even beginners will be able to do a correct analysis of an instrument after a short period of learning!

    The Ronchi eyepiece consists of a metal body with a 1.25" shaft made of black anodized aluminum. It holds a tiny piece of glass with a grating on it. Some gratings from other manufacturers are made of exposed film or laser printouts: Those gratings will show inferior contrast and will be much more difficult to analyze! This Ronchi eyepiece is equipped with vacuum metalized chrome on glass grating with 10 lines per millimeter. The grating is on the telescope side of the glass and is exactly in the same plane as the outer stop. The Ronchi eyepiece is shipped in a protective case with a short manual in English and German.

    OPT Product Number: GN-10-101-150


  • specifications

Product Reviews

Customer Reviews
4.7 Based on 6 Reviews
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Filter Reviews:
    United States United States

    Very useful diagnostic tool.

    Find a bright star. Center in eyepiece. Drop in this Ronchi EP. Rack inside and outside focus til you see five lines (inside and then outside) compare to Ronchi chart. That's it. No arguing with ronchi's supreme authority. Tells you what to fix and if you've fixed it with repeated analysis. Nothing better in the field.

    Canada Canada

    10" mirror testing

    This item performed perfectly. It is easy to use and interpret mirror problems with the included images of typical mirror problems, Thank you.

    Clifton L.
    United States United States

    Easy to use

    After trying my hand at star testing, I couldn't converge to a diagnosis. This is quick and easy. Point at Polaris and focus in and out. The charts with the item and online give a quick diagnosis.

    Attilla D.

    defective, but works fine after I repaired it.

    The ronchi grating in mine fell out. Not properly glued in. I used optical glue to glue my grating back into the eyepiece. That's because I'm in Canada and returning purchases to the USA after importing them is expensive and a pain because of Canada Customs rules. However, now the ronchi eyepiece works fine. I still like OPT, in case you're wondering.

    United States

    Ronchi Eyepiece

    only buy this if your prepared to find out your mirror is a dog, it works quite well in good seeing..m

    United States

    Herd Newman Ronchi eyepiece

    Excellent. I used it in combination with my artificial star to determine the rotational orientation between the primary and corrector plate of a SCT