[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]
Re: [ATM] astigmatism as seen via ronchi?
The expression as derived by Jim Burrows is:
(E^3-C^3)/3*(E^2-C^2) where E is the edge thickness and C is the center
thickness (E minus sagitta).
Don't try it on a flat mirror, though ;-) See
http://web.telia.com/~u41105032/sling/sling.htm
near the end (this gives a quite different value from Dale's expression -
with due respect I trust Jim's more).
Nils Olof
> ummmm....COG of the mirror from front edge = (t/2) - (0.707S) .... ?? any
> available derivation laying around that can be shared....my
> geometry/calculus is rusty...
_______________________________________________
ATM mailing list http://www.atmlist.net/