I guess the main confusion of defining this lens is probably the setting of depth/frequency.
s+#|j;V<
GjTj..G/
The main fresnel lens types are: $7M/rF;N5X
i
T* !3
* Constant groove depth. T.ZPpxY
* Contant groove pitch types. 5A| 4
4cZig\mE;
So if your depth is fixed you will define +ve value in the cell and to specify the "height" or "depth" of each groove feature. If the frequency of the groove is fixed then you use -ve value. Say putting down - 5 this implies that there are 5 grooves with a unit length. WZ}je!8 2
}{FKs!(4
Hope this helps!!
