Those of us who still enjoy taking out the big, old, film cameras of yesteryear sometime get in a bind when contemplating an expansion of our choice of lenses. Most of the ones I can afford don’t come with any instructions and aren’t sold at camera stores (remember them?). I find mine at flea markets, attached to broken gear and, of course, at Photographica, twice a year. This is a list of information sources posted and maintained by Dan Fromm, a photographer who often gives very good advice on APUG.org (a site I frequent and really enjoy). If you come across an old lens at the Photographica show or anyplace else and just can’t resist it, find out what you need to know by going to one of the sites on this list.
I’ve also found the following links really helpful: