After you take Foucault Test Measurements, you need to process, or reduce, the data, to understand the shape of your mirror surface. When this is determined, you can decided which zones to work on, or declare the mirror done.

Before computers were common, the data reduction was done manually. Many of the mirror making books listed in our bibliography will describe the steps to do this. [Texerau84] has the most through description, a nice worksheet to use, and is by far the most popular.

Today, however, most people use a software package running on a personal computer to do this work. These packages will accept a set of Foucault Test Data and produce textural and graphic output that describes your mirror. Surface profiles and transverse error plots will help you decided what your next figuring step should be. Mirror quality metrics, such as wave ratings and Strehl ratios, will help you decide when the mirror meets your completion criteria. The table below lists some of the currently available software:

Screen capture of Figure's Surface Error Analysis screen (Click on it to enlarge)

Page last edited 2007-Sep-23