lentil.translation_defocus

lentil.translation_defocus(mask, f_number, translation)

Defocus error characterized by a axial translation.

Parameters:

• mask (array_like) – Binary [0,1] mask defining the pupil extent to compute the wavefront over.

• f_number (float) – System or beam f-number.

• translation (float) – Axial translation from best focus given in the same units as the resulting OPD.

Returns:

wfe – Focus error due to axial translation

Return type:

ndarray

Warning

Defocus is computed over a circular pupal defined by the maximum horizontal or vertical extent of the supplied mask before applying the mask. As a result, the RMS and peak-to-valley wavefront measurements of the returned OPD will be different than what was requested for non- circular masks.