Optical Instrument Lens

Features

Specifications

• Diameter:
  21.0 millimeters
• End Application:
  Rangefinder mk39
• Axial Thickness:
  1.0 millimeters and 8.6 millimeters
• Compound Lensaxial Thickness:
  9.6 millimeters
• Equivalent Focal Length:
  57.890 centimeters
• Back Focal Length:
  49.650 centimeters
• Front Focal Length:
  60.130 centimeters
• Refraction Index:
  1.6490 and 1.5170
• Compound Lens Style:
  Doublet
• Individual Lens Style:
  Plano-concave and double convex
• Element Left Surface Radius:
  237.9 millimeters and 13.6 millimeters
• Element Right Surface Radius:
  13.8 millimeters and 26.0 millimeters
• Material:
  Glass, optical, jan-g-174
• Federal Supply Class (fsc):
  Optical instruments, test equipment, components and accessories
• National Stock Number (nsn):
  6650-00-320-0802