A | Distance from front edge of lens to front focal point |
BF | Back focal length |
C.A. | Clear aperture |
CT | Center thickness |
D | Distance from back edge of lens to back focal point |
DIA | Diameter |
EFL | Equivalent focal length |
ET | Edge thickness |
f/# | f-number (focal length ÷ entrance pupil) |
FF | Front focal length |
H | Height |
H1 | First principal point |
H2 | Second principal point |
L | Length |
nC | Index of refraction for red hydrogen C line (0.6563 microns) |
nd | Index of refraction for yellow helium line (0.5876 microns) |
nF | Index of refraction for blue hydrogen F line (0.4861 microns) |
R1 | First radius (moving from left to right) |
R2 | Second radius (moving from left to right) |
R3 | Third radius (moving from left to right) |
R4 | Fourth radius (moving from left to right) |
S | Object distance |
S' | Image distance |
V1 | First vertex |
V2 | Second vertex |
W | Width |
D | Abbe constant |