I guess the main confusion of defining this lens is probably the setting of depth/frequency. ,HUs MCXQ
-x:Wp*,
The main fresnel lens types are: r\'3q'7p
`5O<U~'d
* Constant groove depth. E@0wt^
* Contant groove pitch types. +ulX(u(,
/ (W{`
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. RLw=y{%p
`w[0q?}"`
Hope this helps!!