Design Method of Apochromatic System Based on S-L Chart
基于S-L图的复消色差方法

An equation set for apochromatic system has been formulated, which can eliminate longitudinal chromatic aberration and secondary spectrum. At the same time, the normalized coefficient L of longitudinal chromatic aberration and normalized coefficient S of secondary spectrum of optical materials are introduced. With the help of the instructive S L chart, suitable optical materials for the design of apochromatic system can be selected effectively. Finally, design examples of apochromatic system composed of three thin lenses or Petzval objective are given in this article.