The short aperture is for focal lengths up to approx. 85mm
A sun visor, on the other hand, not only protects against incident side or back light, but also against the occurrence of light reflections, as well as against unwanted rain or other negative influences. It is important to ensure that the use of a lens hood always corresponds to the focal length of the lens. A too narrow sun visor is e.g. Always lead to annoying shadows on the corners of the image when used on wide-angle and zoom lenses.