Answer:



The option Separate Fields/Configs  is related to the calculation of tolerance criteria. Your analyzing result is calculated as an average over all fields in all configurations without checking the option of Separate Fields/Configs.  And if the option being checked, the criterion will be calculated and displayed for all fields of view in all configurations individually.

As to fields to be used during the calculation, it is related to the choice under criterion of Tolerancing dialogue, there are three options for Fields, they are Y-Symmetric, XY-Symmetric, and User Defined. So fields used during tolerancie calculation also depend on the option here. The fields will also be listed in the text report after running tolerance. 

•  Y-Symmetric: OpticStudio computes the maximum field coordinate, then defines new field points at +1.0, +0.7, 0.0, -0.7, and -1.0 times the maximum field coordinate, in the Y direction only. All X field values are set to zero.


• XY-Symmetric: Similar to Y-Symmetric, except there are 9 field points used. The 5 Y-Symmetric points are used, and -1.0, -0.7, +0.7, and +1.0 are added in the X axis direction only.


• User Defined: Use whatever field definitions exist in the current lens file. 

Please see full description in the following section of helpfile:   The Tolerance Tab > TolerancingGroup> Tolerancing