The scaler field in the focal volume of nontelecentric apodized focusing sy
stems cannot be accurately described by the Debye integral representation.
By use of the Fresnel-Kirchhoff diffraction formula it is found that, if th
e aperture stop is axially displaced, the focal-volume structure is tuned.
We analyze the influence of the apodizing function and find that, whereas a
xially superresolving pupil filters are highly sensitive to the focal-volum
e reshaping effect, axially apodizing filters are more inclined to the foca
l-shift effect. (C) 2001 Optical Society of America.