Augustin Fresnel divided his dioptric lenses into „orders“
of size depending on their focal distance. The following table gives the
focal distance of the several sizes in millimeter and inches.
Fresnel Lens Orders |
Order |
Focal Length mm. |
Focal Length inches |
Hyper-Radial |
1330 mm |
52.3 inches |
Meso-Radial |
1125 mm |
44.2 inches |
1.Ordnung |
920 mm |
36.2 inches |
2.Ordnung |
700 mm |
27.6 inches |
3.Ordnung |
500 mm |
19.7 inches |
| |
400 mm |
16.7 inches |
| |
375 mm |
14.7 inches |
4.Ordnung |
300 mm |
12.5 inches |
| |
250 mm |
9.8 inches |
5.Ordnung |
200 mm |
8.3 inches |
| |
187.5 mm |
7.4 inches |
6.Ordnung |
150 mm |
5.9 inches |
|