Lens #0: no lens
Lens #1: bi-convex lens 1
Lens #2: plano-convex lens 2,
flat side facing beam
Lens #3: plano-convex lens 3,
flat side facing beam
Lens #4: plano-convex lens 3,
curved side facing beam
major scale units: 1cm,
1 cm hole spacings
Use the mouse to move the lens
and zoom and rotate the view.