Ok, major nooblar question here. Run now while you still can. In looking at various 50mm lenses for my AE-1 P, I've seen some varying descriptions on them. Some state 1.8 or 1.4, and some also have designations like SC and SSC in combination with that. If I understand properly, the 1.4 would let in more light than a 1.8. Would I be better off picking up one over the other, or perhaps one of each? I imagine there's probably specific uses where one is a better choice over the other at times. Before I buy anything, does someone know the differences, or perhaps have a link I could use to research them? Thanks!