[ATM] Flexed RC

[Richard F.L.R. Snashall]

   In honor of our annual tribute to "a day of ill-mannered frivolity" 
(1 April),
the picture:

http://mysite.verizon.net/rflrs/frc6-90x.gif

indicates the layout of a 200 mm f/10 flexed RC. That graphic actually 
presents
the system focused for seven different object distances.  The entire system
is positionally fixed, except a pass-through primary (BK7).  What does not
show up in the picture, though, is that as the primary moves for 
focusing, it is
also flexed to create a conic ranging from about -0.986 for focusing an 
object
at infinity to about -0.64 for focusing a 2.5 m distant object.

The prescriptions are presented for infinity, 80 m, 40 m, 20 m, 10 m, 5 
m and
2.5 m object distances:

http://mysite.verizon.net/rflrs/frc6-90x1.atm   ATMOS input file (inf)
http://mysite.verizon.net/rflrs/frc6-90x2.atm   ATMOS input file (80 m)
http://mysite.verizon.net/rflrs/frc6-90x3.atm   ATMOS input file (40 m)
http://mysite.verizon.net/rflrs/frc6-90x4.atm   ATMOS input file (20 m)
http://mysite.verizon.net/rflrs/frc6-90x5.atm   ATMOS input file (10 m)
http://mysite.verizon.net/rflrs/frc6-90x6.atm   ATMOS input file (5 m)
http://mysite.verizon.net/rflrs/frc6-90x7.atm   ATMOS input file (2.5 m)

http://mysite.verizon.net/rflrs/frc6-90x1.len   OSLO input file (inf)
http://mysite.verizon.net/rflrs/frc6-90x2.len   OSLO input file (80 m)
http://mysite.verizon.net/rflrs/frc6-90x3.len   OSLO input file (40 m)
http://mysite.verizon.net/rflrs/frc6-90x4.len   OSLO input file (20 m)
http://mysite.verizon.net/rflrs/frc6-90x5.len   OSLO input file (10 m)
http://mysite.verizon.net/rflrs/frc6-90x6.len   OSLO input file (5 m)
http://mysite.verizon.net/rflrs/frc6-90x7.len   OSLO input file (2.5 m)

http://mysite.verizon.net/rflrs/frc6-90x.txt    TEXT prescription (multi)

http://mysite.verizon.net/rflrs/frc6-90x.zmx    ZEMAX input file (multi)


The system has fifteen surfaces, so, unfortunately, it may not be usable
in the free versions of OSLO and ATMOS.

The selected wavelengths in the prescriptions go from 350 to 1000 nm.  I
used a weighting function that models chip sensitivity (from Scott
Milligan).  The Strehl ratio for that spectrum is better than 0.9 over
field and focus.