Folk wisdom in optical design

Building optical systems that actually meet specificationsrequires more than a knowledge of optics and the use ofcontemporary design codes. Excellence also comes with akind of "street" knowledge, learned not from textbooks butfrom experience, mostly from failures. These hard-won lessons are colloquially described here as "folk wisdom." If considered during system conceptualization and design,these notes may improve efficiency, effectiveness, and uitimate performance. Costs, mechanical constraints, parts choice, specification and procurement, available adjustments,alignment sequence and retention, deterioration of performance with aging, and other topics are considered.