Some manual focusing lenses are nearly impossible to focus accurately on the pens, even with the focus assist (zoom) activated. others are not bad. I find that the Konica lenses (prime), are a bit easier to get critical focus, than the OMs. I am an old OM user and love them. They look better, are smaller, and have very nice imaging. Just something about the way lenses "come to focus." I have used most of the 35mm brands lenses, over the years, but am most recently using just OM, Konica, and Vivitar. If you want to have any satisfaction using legacy lenses, buy good glass, recommended by the old timers here, that have proven what works best on the Pens. The pens are special, but need the right companion glass to really shine. I just came in from my morning walk, carrying the Ep-2 with the Konica 52mm, f1.8. Solid performance, though a bit heavy.