  Custom optics is a necessity for many imaging applications. Unfortunately,
custom lens design is costly (thousands to tens of thousands of dollars), time
consuming (10-12 weeks typical lead time), and requires specialized optics
design expertise. By using only inexpensive, off-the-shelf lens components the
Lens Factory automatic design system greatly reduces cost and time. Design,
ordering of parts, delivery, and assembly can be completed in a few days, at a
cost in the low hundreds of dollars. Lens design constraints, such as focal
length and field of view, are specified in terms familiar to the graphics
community so no optics expertise is necessary. Unlike conventional lens design
systems, which only use continuous optimization methods, Lens Factory adds a
discrete optimization stage. This stage searches the combinatorial space of
possible combinations of lens elements to find novel designs, evolving simple
canonical lens designs into more complex, better designs. Intelligent pruning
rules make the combinatorial search feasible. We have designed and built
several high performance optical systems which demonstrate the practicality of
the system.
