Hi Shel, I believe that the "SMC Pentax 1:1.2 50mm" is the later version of the K50/f1.2 because the "mm" in the name of K series lenses exists only for K series lenses that were still made while the M series lenses were already there. As I understand it, my "SMC Pentax 1:1.8/85", my "SMC Pentax 1:3.5/135" and my "SMC Pentax 1:5.6/400" were produced before Pentax introduced the "SMC Pentax-M 1:2 85mm", the "SMC Pentax-M 1:3.5 135mm" and the "SMC Pentax-M 1:5.6 400mm". Most of the other K series lenses that I own, e.g. the "SMC Pentax 1:1.2 50mm" or the "SMC Pentax 1:2.5 135mm", have the "mm" in the name. They are lenses which were not replaced by M lenses. Probably most such K series lenses exist in two versions, one with the "/", one with "mm".
Whether the coatings of the different versions differ much I am not sure, but the coating of my "SMC Pentax 1:1.2 50mm" surely looks different from the coatings of the "SMC Pentax 1:1.8/85" and of the "SMC Pentax 1:3.5/135". Arnold > What leads you to believe that the "SMC Pentax 1:1.2 50mm" is the "second" > or later version, and that it has better coatings than the other lens, > which you feel is an earlier version? How can you tell which was produced > first and that there is really any difference between them other than the > way they're labeled? - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
