Shack Hartmann SN=A2

SH spot pattern with 10mm µlens Focal length : the bow shape of the spots is due to the collimator abberations; not the array.
The diffraction theory yields to a 40µm (7.26pixels) radius from spot pic center to the 1st black ring. 7/8 pixels have been measured, so this system has diffraction limited microlenses.