STF - Smooth Trans FocusThis 100 mm mid-range telephoto prime lens is a superb creative tool that offers outstanding G Master resolution plus innovative STF (Smooth Trans Focus) optics for magnificent bokeh. It features fast, precise, quiet DDSSM autofocus, and close-up capability up to 0.25x magnification. Built-in Optical SteadyShot image stabilization minimizes blur that can occur during low light or macro shooting.Exemplary G Master resolution and bokehAdvanced optics and design achieve extreme resolution and absolutely breathtaking bokeh that combine for overall performance that epitomizes the G Master concept.Bokeh doesn't get better than thisThis lens has been specifically designed to produce extraordinarily smooth, natural bokeh without vignetting. The result is naturally immersive depth and dimensionality.Extreme image-wide resolution and sharpness fulfill the demanding 50 lines per millimeter MTF requirement that is the basis of G Master optical design.AF that lets you concentrate on creatingDDSSM (Direct Drive SSM) focus drive provides fast, precise, quiet autofocus, allowing the user to concentrate fully on capturing superlative stills or movies.Lens Controls1. Focusing ring / 2. Aperture ring / 3. Macro switching index / 4. Macro switching scale / 5. Focus hold button (customizable) / 6. Aperture click switch / 7. Focus mode switch / 8. Shake compensation switch / 9. Macro switching ring / 10. Macro switching unlock button / 11. Mounting index / 12. Aperture2 scale / 13. Lens contacts / 14. Lens mount rubber ring / 15. Aperture index / 16. Lens hood indexSpecificationsLens MountSony E-mountFormat35mm full frameCompatibilityE-mount 35mm Full Frame E-mount APS-C camerasFocal Length (mm)100mm35mm Equivalent Focal Length (APS-C)(mm)150mmLens Construction (Groups, Elements)8 groups, 11 elements (Excluding APD Element)CoatingNano AR CoatingMaximum aperture (F)f/2.8 (T5.6)Minimum Aperturef/20 (T22)Angle of View16 degree (APS-C) 24 Degree 35mmNumber of Aperture Blade11 circularCircular ApertureYesMinimum Focus Distance0.85m/2.79' with the Macro Switch set to 0.85m 0.57m/1.87&