> I'm not sure, but I believe there were two ST 35/3.5 lenses, one > that stopped to f16 and another to f22, and that they were different > optical formulas.
>From what I can tell, there were indeed basically two versions of the ST 35/3.5, although to my eyes they optically seem not all that different (at least, both seem to have the same or a very similar 5/4 configuration). The earlier one could go either to f/22 (the "older older one") or to f/16 (the "newer older one"). The later version went to f/16 only. It seems to me that the easiest way to tell them apart is that the later model has a "cutout" on the barrel for the DOF distance scale (looks a lot like many of the K and M lenses), while the earlier model lacks the "cutout". I have no idea as to whether there were any significant optical differences between these models, but apparently the last batch(es) of the later model may have received the SMC coating treatment. Fred
