The Sony 135mm f/2.8 [T4.5] Smooth Transition Focus lens is one of the most exotic lenses available for a 35mm camera: it's a 135mm manual focus-only lens designed specifically to produce high-quality bokeh -- the out-of-focus part of the image. It was first developed by Minolta in the early 1990s and then re-released by Sony when they took over Konica Minolta's camera business in 2006.

The STF is not a "soft focus" lens: the in-focus parts of the image are razor-sharp. Rather, the lens uses a special apodesical element to provide superb defocussing of the background and smooth transitions between in-focus and out-of-focus areas.

I first tried out a sample in June 2009 at a Sony user event at the Dr. Sun Yat-Sen Gardens in Vancouver, and was recently able to pick up a copy of my own. Here are some of my favourites.