The Sony FE 100mm f/2.8 GM STF OSS is part of Sony's G Master series of lenses and provides superb optics for both full frame E mount Sony cameras and APS-C E mount cameras. This mid-telephoto prime offers Smooth Trans Focus (STF) that uses an apodization filter (like a radial neutral density filter) to produce smoother bokeh (out of focus areas) to contrast nicely with the sharpness this lens can produce. Optical layout has also been designed to reduce peripheral highlight distortion due to vignetting in order to achieve rounder out-of-focus highlights in both the foreground and background. For this reason, it is an ideal portrait lens, especially for those who like to shoot wide open. The robust construction and dust/moisture sealing makes this a great choice for outdoor use and the image stabilization system supports the minimization of camera shake when shooting handheld at slower shutter speeds, which is good for low-light work and shooting during a fading sunset. The ever-handy focus hold button on the lens body helps you hold your focus position or you can use your camera to customize it for a lens function of your choice. There is a macro ring switch that will extend the lens' range for a minimum focusing distance of 1.87'. The manual aperture ring can be de-clicked for when you'd like silent aperture changes while shooting video and the Direct Drive SSM focus drive provides fast, precise, quiet autofocus that's also suitable for video work. This lens is ideal for portrait photographers, wildlife, fine art, and for mid-telephoto videography.