Pentacon 50mm f/1.8

Searching ebay for new toys, I stumbled on an auction for an old East German lens complete with the adapter to attach it to the micro-four-thirds mount of the Panasonic camera. These things were mass produced in a former decade and, well, aren't really so great optically, so they are available on ebay for very cheap. Other than the retro appeal, the main feature is the big aperture.

   
The sharpness leaves something to be desired, but for retro analog goodness it does deliver. And narrow depth of focus, too: the background is not just defocused but obliterated, swimming with that sought-after bokeh. Hitting a moving target with the aperture fully open using the manual focus is pretty much a lost cause. For targets moving faster than a plant or a coffee mug... f/1.8 might not be the right choice. Which is a pity because moving targets are exactly when you want a faster shutter speed.

   
Here's some guy's page about the lens: http://lewiscollard.com/lenses/pentacon-50mm-f1.8/