All our objectives are guaranteed to have a minimum of .96 Strehl in green light and are optimized for the wavelengths where eye is most sensitive, 555 - 560 nm.

· Manufacturing specifications:
        - Strehl ratio better than 96% at 532 nm.
        - Wave front error p.t.v. is no more than 0.166 of wave-length at 532 nm.
        - Surface finish: IV class according to 11141-84

· Dimensions of scratches and points/inclusions shall not exceed the following values:
   · Scratches with less than 0.02mm width:
        - Number of scratches: less than 0.1 clear aperture
        - Total length of scratches: less than 1 clear aperture.
   · Points with less than 0.3mm diameter:
        - Number of points: less than 0.25 clear aperture
   · Total area of all defects: less than 0.05 clear aperture (mm2)

   · Multiple layer coatings on front and back surfaces. Reflectivity = 0.25%/surface.

   · Slight color variations in the light reflected from anti-reflection coatings are allowed.

   · Bubbles and inclusions in glass material are allowed under 0.5mm diameter. Maximum number of bubbles and inclusions is 2 pieces per lens. Bubbles and inclusions under 0.03mm diameter are disregarded.

Pal Gyulai
Optical Designer
CFF Telescopes