When I mount my kit lens to the D5100, it "clicks" into place. When i mount the 50mm AIS, it rotates in place, but gets "tight" before i ever hear a click. Doesn't seem to rotate far either. I don't want to force it and damage anything! Help!
Welcome to Nikonians! You should not have a problem mounting an AIS lens on the D5100. Did you align the alignment dot on the lens with the alignment dot on the camera body? Good Luck and Enjoy your Nikons!