This article is also available in Japanese.

There are many analysis features in ZEMAX that allow you to evaluate optical performance both at the defined image surface as well as intermediate surfaces. This capability makes it easy to evaluate intermediate image locations in an optical system. Here is just a few of the features that support such evaluation:

• Ray fans
• OPD fans
• Wavefront maps
• PSF plots
• MTF plots

You can even optimize at surfaces other than the defined image surface using the IMSF operand.  For information on using this operand, please see the Knowledge Base article “How to Optimize at Intermediate Surfaces”.

Care must be taken when evaluating performance at intermediate surfaces.  There are a number of assumptions that ZEMAX makes when performing intermediate surface evaluation.  For full details on these assumptions, please see the section entitled “Fans”, sub-section “Ray Aberration”, sub-section “Evaluating results at intermediate surfaces” in the “Analysis Menu” chapter of the ZEMAX manual. The next page describes a very important consequence.