Canon CaF2 & MgF2 – 2

See a previous page first if missed. 

The entire process until the completion of polished fluorite lenses is as follows


Click to enlarge to read


3 major examples. From left, Canon telephoto lens, BORG 107FL and Smithsonian Observatory

I has also realized Canon Optron has the largest market share for wide variety of optical coating in Japan. They are not only AR coat for lenses, optical filters and mirrors, but also anti-static and hydrophilic coating etc, various applications. So they are the complete provider from making a fluorite crystal to polishing a lens and coating.

According to Canon, MgF2 is used for coating on BORG fluorite lens.


To BORG fluorite owners, be proud your fluorite lenses are produced by such a highest-ranking optical manufacturer. Enjoy the astronomy through the high-quality optics.  

~ by tedishikawa on March 13, 2019.

4 Responses to “Canon CaF2 & MgF2 – 2”

  1. If only you couldbring back a few 90fl elements in your suitcase 🙂

    • Paul,
      I’m fully sure we can ship your 91FL f3.9 to you within this month. All parts are ready in Japan. Only problem is their paperwork as a new package. I really appreciate your patience.

      • Np. Thanks Ted. Am I right in assuming you will be at NEAF in a few weeks? Would love to come to meet you in person, but might be a tad difficult for me to escape this time of the year.

  2. Ted,

    When I use my Borg 71FL on the moon, I am always elated by the sharpness and the contrast when I hit the “sweet point” on focusing, and the image POPS clearly into view.

    Best regards to you and Mia,


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