shadowfox
Darkroom printing lives
1. Which OM screen (I have OM2's but I plan on getting OM1's) would you recommend for manual focusing portraits? Most likely my glass was too slow but I had difficulty focusing my 28mm f3.5 (I'll get a 28mm f2.0, next).
2. This is probably a bit messy but would a Nikon F2/F3 be easier to focus? What about Canon F1's? I read that Nikons have less brightness but more contrast.
Okay, let's answer your questions then:
1. You are using a 28mm, which is a wide angle lens. So it's naturally harder to focus because you see a whole lot of details in the viewfinder. Changing focusing screen to an even brighter one like 2-13 (OM-3 and OM-4 only) may or may not help. If you want to seriously use OMs for portrait, obtain the Zuiko 85/2, then the focusing screen will help.
2. No experience with F2 or Canon F1. I have no problem focusing with F3 though.