I use this TC with Minolta 400/4.5 HS APO in combination with Sony A77ii and a99 bodies. To be honest I don't see any deterioration in image sharpness and the autofocus functionality is retained when used with this lens. It's expensive, but worth paying for the image quality unless you're lucky enough to find a good used Minolta 1.4x APO II TC (which is essentially the same design and build, but heavy can be found).