The M.Zuiko Digital ED 40-150mm f/2.8 PRO from Olympus is a versatile 80-300mm equivalent telephoto zoom for Micro Four Thirds mirrorless cameras. As part of the PRO series of advanced lenses, this zoom distinguishes itself with a bright f/2.8 constant maximum aperture for consistent illumination throughout the zoom range to suit working in a variety of lighting conditions.   A manual focus clutch permits quick switching between AF and MF, and programmable L-Fn button avail lens-based control over shooting settings. The lens is also weather-sealed for working in trying conditions, and a removable rotating tripod collar is included for improved balance and support when working atop a tripod or monopod. One aspherical ED (extra-low dispersion) element, two aspherical elements, one Super ED element, three ED elements, and one HD element are featured within the optical design to minimize both spherical and chromatic aberrations, distortion, and color fringing throughout the zoom range while also contributing to overall image sharpness, clarity, and color accuracy. A Dual VCM (voice coil motor) system is used for quick and near-silent autofocus performance. By separating the focusing mechanism into two groups controlled by separate linear AF motors, focus speeds are faster and the friction-free movement is notably quieter to benefit video recording. Dust-, freeze-, and splash-proof design uses 11 separate seals to ensure the lens's performance in inclement and harsh conditions. A removable rotating tripod collar offers a stable platform for working with this lens atop a tripod or monopod.