when maximal aperture was same, but a shorter focal-length lens is usually with larger AF-error showed up in the maximal aperture. (despite the Nikkor 35mm f1.4G and 35mm f2D were with better state, but general cases still exist of foregoing that.)
when the focal-length was same, but a larger aperture lens is usually with larger AF-error showed up in the maximal aperture.
well then, the larger aperture of wide-angle lens existed of more difficulties.
excepting the macro lens, why the many lenses are such cases? (a short distance target and the AF-error in maximal aperture)
In essence, the said two situations actually have a same intrinsic factor, the off-axis beams of light have the higher obliquities would easily lead to a larger spherical aberration, and thus the autofocus-error will be risen, (for the PD-AF in maximal aperture).
However, looks the PD-AF having the larger focus-error in maximal aperture if got large spherical aberration, but the optimum imaging aperture is still to be likely a good accuracy AF, when lens had having a not bad design. The optimum aperture's imaging performance needed to get a priority consideration, that is frequently saw things.
Commonly, the maximal aperture's spherical aberration correction had to make the necessary compromises. Most of the designs were impossible to take blindly pursued the spherical aberrations get a zero, which is also impossible thing in fact.