Well, and the marginal difference between the 50/1.4, 50/1.7, and 55/1.8 is so small as to make it hardly worth pursuing one or another. They're all among the few lenses capable of generating more resolution than most films can record.

I've got a radioactive 50/1.4, recently cured of most of the yellowing by a prolonged sun bath -- and now the meter in my Spottie is acting up. Sigh...