[ATM] additional lurie-houghton degrees of freedom

[vladimir sacek]

Richard in the UK wrote:

> (Dimensions in millimeters)
> Surf     Radius  Thickness     Glass  Diameter Conic
> OBJ   Infinity   Infinity                   0     0
> STO   1738.874      17.78    N-BAK4     95.25     0
>   2   -4729.94       2.54               95.25     0
>   3  -1738.874      10.16    N-BAK4     95.25     0
>   4    4729.94      914.4               95.25     0
>   5      -2032  -1014.116    MIRROR     101.6     0
> IMA   Infinity                       35.66137     0

I noticed it doesn't agree with my radii values 
(R1,3=+/-67.42" and R2,4=-/+175.96"). Other than 
going with the e-line (as opposed to d-line used by the calculator), 
which accounts for negligible difference, I was taking the 
mirror r.o.c. as -2000mm (there's always danger lurking in 
switching back and forth from mm to inches). When using 
correct radius value (-80", or -2032mm), I get R1,3=+/- 68.46" 
and R2,4=-/+186.21", practically identical to those with the calculator.

It's still good for me to have you around...

Vlad