WHAT ASPECT OF THE PROBLEM WAS MOST DIFFICULT? 
Finding the basic optical configuration. 

WHAT INSIGHTS (IF ANY) DID YOU GAIN FROM WORKING ON THE PROBLEM? 
The global search routines need more development. 

ADDITIONAL COMMENTS: 
The computer ran for days (and nights) when I was doing the 
global searches and hammer optimizations. I even had it run 
when I was away or asleep. I could never have done this if 
I had not had my own computer with ZEMAX plus lots of free 
time. Yipes! 

This problem was an exercise in using the combined global 
search, hammer, and damped least-squares optimization options. 
It also was an exercise in using the designer's intuition about 
what a good solution should look like (although that may have 
been a trap!).