Three thermal effects--variation of image location, variation of focal length and longitudinal chromatism--are described in the form of formulas, which include surface distributions proportional to the thermal constants. Principles for the optical system athermalization by means of optical (passive) compensation and thermooptical (active) compensation are given. The problem of proper selection of thermal material constants and mechanical constants of lenses and mounts is discussed. The condition for achromatization in the form of the formula including material distributions and the principle of material selection is given. #1997 Society of Photo-Optical Instrumentation Engineers, S0091-3286(97)00206-7
展开▼
