Sometimes, while designing imaging optics inside while the mind is outside in the sun, designer gets visitors either unexpectedly of summoned by subconscious. Considering some of the visitors, I'd like to think the 'unexpected' is the correct one.
This little fellow appeared while designing a five lens objective of a very fast aperture. It was the season and I could hear the real ones chirping away, so he might have been a subconscious embodiment embedded in the damped least squares algorithm.
The following, a focal reducer to the former design, was definitely subconscious, being prior to a trip to the beach.
Some of the dangers of wild (or, long undergrowth like one encounters in mountain hikes) also reared their ugly heads in the middle of an objective design, although long pants even in the heat is an easy way to avoid these little buddies.
Optical designing in summer... just as random as diverging optimization run.