It seems that sometimes I go to a shop ask a specific thread size for a step down ring, the shop saleman will ask me whether it fits the lens side or the camera side. I thought when I mentioned step down ring they should understand what I am talking about right??? Like for example I am asking for 58-52 step down ring type, it is obviously 58 for camera thread and 52 for filter attachment. Am I making a mistake here? Out of 4 shops, only 2 shops didn't ask and I get what I wanted.