I've recently purchased this lens for my Nikon D3200. I'm not used to the focus ring AF/MF switching. When fitting ND filters etc, I normally set my camera up, focus set, switch to MF and then after fitting the filters, take my shot. Its easy to switch to MF on my Nikon and Sigma lenses as they have standard lens switches. When moving the Tokina from AF to MF, I notice that the ring can turn slightly and maybe this affects the focus? I've not used the lens yet so cant say this actually happens. Its just an observation when I've taken it out of the box. Can anyone comment?