The Olympus OM System Zuiko 75-150mm f/4 is a telephoto zoom lens designed for the Olympus OM series of 35mm SLR cameras. Launched in the mid-1970s, it became a popular option for photographers looking for a lightweight and versatile zoom lens that covers a useful focal range for portraits, sports, and general telephoto work. The Zuiko 75-150mm f/4 became popular for its affordability, portability, and the balance it strikes between performance and convenience, especially for photographers needing a versatile zoom lens without the bulk.