Lens width..................................2a
Lens sag.....................................h
Radius of curvature.....................Rc
Effective front focal length...........f FFL
Effective back focal length...........f BFL
Focal length in glass....................fg
Refractive index of glass..............n
Wavelength................................λ
Conic constant...........................CC
Effective front focal length |  | |
Effective back focal length |  | |
Focal length in glass |  | |
Numerical aperture |  | |
F - number |  | |
Fresnel number |  | |
Lens sag |  | |
1 rad = 57.296° 1° = 17.45 mrad