E-89-681 40mm Dia. x 50mm FL, MgF2 Coated, Achromatic Doublet Lens
E-89681 40mm Dia. x 50mm FL, MgF2 Coated, Achromatic Doublet Lens
Diameter (mm): 40.00 +0.0/-0.025
Effective Focal Length EFL (mm): 50.00
Focal Length Tolerance (%): ±2
Back Focal Length BFL (mm): 34.46
Focal Length Specification Wavelength (nm): 587.6
Clear Aperture CA (mm): 39.00
Centering (arcmin): <1
Center Thickness CT 1 (mm): 19.00
Center Thickness CT 2 (mm): 7.00
Center Thickness Tolerance (mm): ±0.1
Radius R1 (mm): 28.56
Radius R2 (mm): -29.97
Radius R3 (mm): 153.67
Edge Thickness ET (mm): 16.52
Surface Quality: 40-20
f/#: 1.25
Numerical Aperture NA: 0.40
Coating: MgF2 (400-700nm)
Coating Specification: Ravg ≤1.75% @ 400 - 700nm
Power (P-V) @ 632.8nm: 1.5λ
Irregularity (P-V) @ 632.8nm: λ/4
Bevel: Protective bevel as needed
Type: Achromatic Lens
Wavelength Range (nm): 400 - 700