 |
| English | German |
| chief ray | Hauptstrahl (the ray from any oblique object point passing through the centres of the iris and pupils of a lens, the ray midway between the extreme upper and lower rim rays, or the ray through the centre of the aperture) |
|
| English | German |
| chief ray | Hauptstrahl (the ray from any oblique object point passing through the centres of the iris and pupils of a lens, the ray midway between the extreme upper and lower rim rays, or the ray through the centre of the aperture) |