Sensitivity of null to tip (left) and coma (right) for six fibers. Blue and red for fibers 1 and 4, placed in the direction of the aberration. Brown represents fibers 2 and 6 (which overlap due to symmetry), and purple represents fibers 3 and 5 (also overlapping). Black represents the average of the six fibers for all orientations of the aberration. The tolerance limit is shown with the dashed black line.