The optical design considerations for a 10 micrometer scanning catadioptric optical system are discussed. The system scanning concept is an extension of previously developed can methods. Although systems of this form have traditionally been refractive, certain situations permit use of a reflective Cassegrain as the prime collecting optics. The Cassegrain with two piano convex germanium elements represent the simplest and fewest number of components with which to accomplish the task. The design and assembly philosophy, tradeoffs, and final optimized design are reviewed. The system was fabricated, and performed as predicted.