2012 Volume 33 Issue 3 Pages 109-114
Point spread function (PSF) and optical transfer function (OTF) are described. The PSF figure is affected by aberrations of the optics, diffraction effect of pupil and diffraction within the optics. When the aberration effect is smaller than the diffraction effect, the pupil function, together with the wavefront aberration, is transformed to PSF by Fourier transform. When the aberration effect is larger than the diffraction, effect, PSF is obtained directly via ray tracing of geometrical optics. OTF is obtained via Fourier transform of PSF, its absolute value being defined as modulation transfer function and its phase value as phase transfer function. Some physical meanings of these concepts are explained.
