レンズに関する各数値の光学的定義
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
Numerical aperture：NA
F-number：F|#
Fresnel number：FN
1 rad = 57.296° 1°= 17.45 mrad