ABSTRACT
In this entry, we present the rules of real ray tracing step-by-step; these rules are explained in a clear language and same examples are included for the first-time readers. Real ray tracing is presented in a self-explanation form to make this contribution readable in itself. The Snell law is revisited and adapted for its implementation in a numeric algorithm. The spot diagrams resulting from a real ray-tracing calculation are discussed. The wave nature of light propagation can be also approximated by using real ray tracing. Therefore, we show the method to calculate a geometrical wave front and also its intrinsic limitations. Linked with the spot diagrams, it is possible to evaluate a point spread function. Also, an optical transfer function and a modulation transfer function are defined within this geometrical approach. The evaluation of the flow of energy through the system is discussed within the ray-tracing framework. (Some hints about the inner mechanisms used by the optimization procedures of optical systems are discussed and related with a basic classification of the software packages currently used.)
