I guess the main confusion of defining this lens is probably the setting of depth/frequency. IP(Vr7-v ypy68_xyW The main fresnel lens types are: Nd; K u6 S;)w. * Constant groove depth. Y*14v~\' * Contant groove pitch types. f\jLqZY #E&80#Z5 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. ` eXaT8 Pqn@ST Hope this helps!!
