I guess the main confusion of defining this lens is probably the setting of depth/frequency. /q"d`!h)w
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The main fresnel lens types are: &Ky u@Tt
yw* mA1v
* Constant groove depth. NB
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* Contant groove pitch types. = yTa,PY
X=p3KzzX
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. XHZ:
mLf
a ?,[w'7FU
Hope this helps!!
