Pentax Super-Multi-coated Takumar f/1.4/50mm lens.

My Pentax 50mm f1.4 lens focus ring was slipping. I unscrewed the lens ring with a rubber ring, then unscrewed 3 black tiny PH00x40 Phillips head screws, which is the filter ring, which gave me access to the 3 Phillips head screws sitting on a brass ring, tighten those 3 and no more slipping barrel. :)

Done