Delivering both smooth bokeh and fine sharpness, the FE 100mm f/2.8 STF GM OSS from Sony is a short-telephoto prime featuring a unique and sophisticated optical design. Separating itself from other portrait-length lenses, this 100mm f/2.8 features Smooth Trans Focus (STF) technology, which uses an apodization filter to realize notably smooth bokeh with rounded out-of-focus highlights in both the foreground and background.