Optical Instrument Lens

Features

Specifications

• Diameter:
  Between 1.097 inches and 1.100 inches
• Axial Thickness:
  Between 0.241 inches and 0.251 inches
• Equivalent Focal Length:
  -0.927 inches
• Back Focal Length:
  -0.961 inches
• Refraction Index:
  1.6890
• Abbe Constant:
  30.900
• Single Lens Style:
  Double concave
• Element Left Surface Radius:
  2.774 inches
• Element Right Surface Radius:
  0.860 inches
• Material:
  Glass, optical, mil-g-174, grade c, type 689-309
• Fsc Application Data:
  Periscope, tank
• Federal Supply Class (fsc):
  Optical instruments, test equipment, components and accessories
• National Stock Number (nsn):
  6650-00-768-8771
• Special Features:
  Left surface edge chamfer 0.010 to 0.020 in. By 45 deg. Right surface edge chamfer 0.050 to 0.060 in. By 45 deg. Both surfaces coated with magnesium fluoride. Rim and chamfers ground.