EastNeuk
Established
The MC-Rokkors with the deeply scalloped metal focus rings, like this one,^ are my favorites. I realize the later Rokkors with smaller filter ring sizes are probably optically "better" (mainly due to improved coatings), but they don't seem as well made.
I'll just add my two pennies and say that while the 58 f/1.2 has a deservedly excellent reputation, based on what I've seen, I can attest that the 58 f/1.4 is also a worthwhile lens. I got mine at $80 in excellent optical shape with some minor cosmetic infelicities. I've only shot it via an adapter on a Ricoh GXR, but the results were quite wonderful for portraits. I like it enough that I may by a SRT 102 one day to go with it.