Full Version: 2 Fresnel Lens Calculator
Does anyone have this please to post here? That would be the focal length of 2 fresnel lenses jointed back to back or spaced.
(F1*F2) / (F1+F2-gap)=EFL
QUOTE (DAZZZLA @ Aug 31 2007, 06:33 AM) 
(F1*F2) / (F1+F2-gap)=EFL
Thanks so i get 220 x 220 /440 = 110mm EFL with zero gap and 2 x 220mm fresnels
Is this correct?
Yes.
If you are using 2 fresnels with the same FL and no gap you can just divide one of the FLs by 2.
DJ
If you are using 2 fresnels with the same FL and no gap you can just divide one of the FLs by 2.
DJ
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