Dan ,

I respect your abilities and experiences.

If you want to calculate a lens with computer as much as for ideal conditions it takes more than 1000 years for Summicron 50.

Think you have 14 surfaces with each surface is precise as 0.99999 and you have 7 distances , 7 thickness each of them 5 digit sensitive , 35 glasses each have 5 digit sensivity

Let us calculate , multiply 11111 x11111x11111x11111x11111 , least 35 times and you are the expert how big the problem is ?

The problem is to find a mathematical way to shortcut this problem. Only few companies have ability and will to do that , thats why Leica sells his last lens for 6000 euros.

Umut