Relating wavefront error, apodization, and the optical transfer function: on-axis case: comment.

In a recent paper [J. Opt. Soc. Am. A31, 2476 (2014)JOAOD60740-323210.1364/JOSAA.31.002476], a linear expansion of the optical transfer function (OTF) of an imaging system in which the expansion coefficients are related to its wavefront errors has been developed. It is claimed that the OTF can be calculated quickly by using this approach. We provide instead closed-form basis functions that are not determined recursively. Numerical examples demonstrate that the OTF calculation by a digital autocorrelation of the pupil function is much faster regardless of the wavefront complexity.