Originally posted by Roadboat24 I use a Rokinon 85mm f1.4 on K50, K3 and K1. Manual focus but I'm happy with it.
I have one as well. Absolutely wonderful, I can't recommend it highly enough. Just bear in mind that manual focus using ye olde optical viewfinder is a challenge. If you were glasses, two words of advice on the OVF: forget it. Live view, preferably with magnification, is the way to go.
Originally posted by pentaxus I have an old 50mm 1.4 F series lens that I like for portraits.
Good advice. I have an M 50/1.4 that also works well.. For AF this is a lot cheaper than the 85/1.4. MF is slightly easier than the 85/1.4.
From what I have read, the AF technology inside a DSLR have the same challenges with large apertures that humans eyes have. The AF 50/1.4 and the AF 85/1.4 are both known for slow(ish) focusing.