Summary

This article has discussed :

• The meaning of the f/# in optical systems with non-circular stops
• The theoretical basis of the defined effective f/# calculation in ZEMAX

External References

1.  For an explanation of what a Pechan prism is, see, for example, Design and Mounting of Prisms and Small Mirrors in Optical Instruments, by Paul R. Yoder, Jr., (SPIE Press, Bellingham, WA, 1998), pp. 41-42.
2.  Ronian H. Siew, "f/No. and the radiometry of image forming optical systems with non-circular aperture stops," in Optical Modeling and Performance Predictions II, Mark A. Kahan, editor, Proceedings of SPIE Vol. 5867 (2005).
3.  V.N. Mahajan, Optical Imaging and Aberrations (SPIE Press, Bellingham, WA, 1998), pp. 108-118.
4.  Zemax Optical Design Program User's Guide, ZEMAX Development Corporation.