Got an old Vivitar lens today. It's f/2.5, 28mm which is around 60mm on my Olympus E-M5. First impression? It looks absolutely awesome on the E-M5. The old-school look is really cool.
It's heavy, very heavy. It's soft at f/2.5 but it gets very sharp starting at f/2.8. The bokeh is gorgeous. The flares are also really nice (if you're into flares in the first place).
It was only my first day with it today, and I need to get used to shooting with fully manual lens (no autofocus, aperture needs to be set with a ring on the lens, not with a dial on the camera body). It takes time to get used to. EVF helps a lot.
And the best part? It was $30 + the cost of the adapter.
I made this pic available for free, so you can download full resolution to see how sharp it is in the middle of the frame.