I just received my Tamron 35mm f1.4Di lens and it seems to have a huge back focus issue. I'm using it on a Nikon D800 and have adjusted to the maximum allowable Micro-Adjust -20, however it is still back focusing by a fair margin. Has anyone else had this issue with the lens. I'm waiting on the Tamron Tap-in hardware to arrive, but i'm concerned the maximum adjustment available in it will not fix the issue. Could it be that my body and this particular lens are just not going to work together?? I've only ever owned Nikon lenses and never had to micro adjust any of them.