| MadSci Network: Engineering |
This is a very interesting question. Of course, you could achieve magnification with an objective lens at the entrance to the periscope, and use an eyepiece (ocular) for focussing at the exit. A ray tracing program could provide the particulars as to the radii of curvature and focal lengths that would be necessary. This would be based on the sizes of the periscope and the degree of magnification required. (A little experimentation with surplus lenses would also give good results.) Another possible solution would be to model the optics after a Newtonian reflecting telescope: that is, use a concave parabolic or spherical mirror at the first elbow (instead of a flat 45 deg. mirror), use a normal flat 45 deg. mirror at the second elbow, then use a telescope eyepiece at the exit for focussing. A quick browse through the Edmund Scientific optics catalog shoudl give you many other ideas, too. Hope this helps. fjc Frederick J. Carranti, P.E. Institute for Manufacturing Engineering 151 Link Hall Syracuse University carranti@ecs.syr.edu
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