They seam to have a flatness of λ/2 - λ/4 and are quite cheap, 10 bucks for a 25mm diameter one (that 1/5 the price of a normal 25mm secondary elliptical mirror)

  • einfach_orangensaftOPEnglish
    2·
    1 month ago

    Silver should have good reflection over most of the spectrum, guess its the coatings making things strange then :/

    • Thorry84@feddit.nlEnglish
      5·
      1 month ago

      I know enough about these kinds of optics to be firmly in the valley of despair on the dunning kruger graph. It’s super complicated and well beyond my understanding.