By Scott Sparrold (under construction)
This is a quick outline for how a lens focal length varies with wavelength shift (color).
Secondary Color and How to compute it
Apochromats
Two element solutions
MWIR: Si / Ge Visible S-FPL53 / S-BSM81 or H-FK61 / H-BAK6
Three element solutions
Have a crazy doublet? Want to know the doublet's equivalent V and P?
Under construction | 
