Focal Lengths: 32mm, 40mm, 50mm, 75mm, 100mm. The Cooke Anamorphic /I SF lenses offer superb optical and mechanical performance. SF stands for "Special Flare". The SF lenses have a specially manufactured lens coating that not only gives a more prominent flare but also enhanced bokeh and other aberrations. This gives cinematographers the option for a more vintage, character rich look. If you are looking for a deeply soulful, cinematic and original look, then these are the lenses for you.