The Fujifilm GF 45-100mm f/4 R LM OIS WR is a versatile medium format G-mount zoom lens covering wide-angle to portrait-length perspectives; it offers a standard zoom of 36-79mm equivalent focal length that is well-suited for a wide variety of shooting applications. Featuring a bright constant f/4 maximum aperture, this lens provides consistent performance throughout the zoom range. Optically, its high-performance optical design incorporates one Super ED element and one ED element to vastly decrease chromatic aberrations and colour fringing throughout the zoom range for improved clarity and colour accuracy. In addition to that, three aspherical elements aid in controlling spherical aberrations, field curvatures, and distortions to maintain accurate rendering and high degree of sharpness. The lens employs a linear AF (autofocus) motor for fast and quiet focusing performance that suits both stills and video applications, while an internal focusing system helps to maintain the overall length of the lens during focusing for faster focusing time. An optical image stabilisation (OIS) system complements the optics by compensating up to five stops of camera shake to deliver sharper handheld imagery. A physical aperture ring on the lens barrels supports intuitive adjustments over exposure settings and the incorporation of a C (Command) position allows for camera-based aperture setting. Working in inclement conditions is possible as the lens is dust-, freeze-, and weather resistant, as well as robustly constructed with magnesium alloy. A rounded nine-blade diaphragm contributes to a pleasing bokeh quality.