With the Kenko Teleplus PRO 300 DG 1.4x AF Teleconverter full autofocus (AF) functioning is possible with lenses having a maximum aperture of f/4 or brighter. Having 1.4x magnification, the Teleplus PRO 300 is constructed of 5 multi-coated elements in 4 groups and allows a depth of field 1/1.4 of the prime lens used and retains the prime's minimum focusing distance.
