[ATM] Zonal Combination

["Richard F.L.R. Snashall" <rflrs@rcn.com>]

I saw a note the other day about the BK7/F3 glass combination
for an air-spaced doublet.  When the constraint that the two
inner radii be equal is added, this combination produces a
low zonal error at the e-line.  Another combination I remembered
was BaK4/SF2.

However, I found another combination in ECO glasses that beats
them both with respect to zonal error (216 mm f/12):

    http://users.rcn.com/rflrs/dbl02-85x.atm   ATMOS input file
    http://users.rcn.com/rflrs/dbl02-85x.len   OSLO input file
    http://users.rcn.com/rflrs/dbl02-85x.txt   TEXT prescription
    http://users.rcn.com/rflrs/dbl02-85x.zmx   ZEMAX input file

The radii are shallow and the longitudinal error is relatively
low, too.  The densities are up there, though, so the doublet
won't be light.

The zonal error bends back, so this design is actually about
lambda/9000 P-V at the e-line.
_______________________________________________
ATM mailing list http://www.atmlist.net/