One of the lenses I’ve accumulated over the last few years that I’ve spent gathering film cameras, is the famous Pentacon 135mm F2.8. It is often referred to as the ‘bokeh monster’ because of the lovely out of focus bits and how they look due to the sixteen(!) aperture blades.
After buying an M42/Canon bayonet adaptor from a nice Chinese man on Ebay (how do they produce this stuff and mail it halfway around the world for less than the cost of an envelope?), I thought I’d see how the lens performs on the greatest camera ever made.
You can read someone else’s entertaining review of the lens here. For me, it’s not very sharp and has all sorts of colour fringing, but that bokeh is ace.