Terminology (Basler Lenses)#
Designations According to DIN 1335#
| O | Object position | f' (=H'F') | Focal length |
| O' | Image position | k (=f'/dEP) | f-number (indicated as "f/k") |
| H | Front principal plane | i (=HH') | Principal point separation |
| H' | Back principal plane | sF (=SF) | Front focal length |
| F | Front focal plane | s'F (=S'F') | Back focal length |
| F' | Back focal plane | sEP (=SP) | Entrance pupil position |
| P | Entrance pupil plane | s'AP (=S'P') | Exit pupil position |
| P' | Exit pupil plane | d (=SS') | Overall optical length |
| S | Vertex of first lens surface | dEP | Entrance pupil diameter |
| S' | Vertex of last lens surface | dAP | Exit pupil diameter |
| ß'P (=dAP/dEP) | Pupil magnification |
Other Designations#
| FB | Flange back | MOD | Minimum object distance |
| MSD | Maximum screw-in depth | CRA | Chief ray angle |
| MBL | Mechanical back length | Inf. | Infinity |
| WD | Working distance | MTF | Modulation transfer function |