OM System's compact PRO standard zoom — 24-90mm equiv at constant f/4 with weather sealing.
The OM System M.Zuiko Digital ED 12-45mm f/4 PRO was released approximately 2020 under the Olympus brand as an ultra-compact PRO-tier standard zoom for Micro Four Thirds, providing constant f/4 with weather-resistant construction in a notably small package. MFT mount.
f/4 constant aperture. 12-45mm zoom range (approximately 24-90mm equivalent on MFT). PRO weather-resistant construction. At approximately 254g. 58mm filter thread. Micro Four Thirds mount.
The 12-45mm f/4 PRO is unusually compact and light for a constant-aperture professional zoom — 254g and weather-sealed represents excellent portability for a PRO-tier lens. The f/4 constant aperture (one stop slower than f/2.8) is the trade-off for the compact size. Pairs well with compact MFT bodies for travel and documentary photography.
On the used market the OM System M.Zuiko 12-45mm f/4 PRO is a compact weather-sealed standard zoom for MFT. Condition checks: weather sealing at zoom ring and barrel, 58mm front element for marks, AF response, zoom ring smoothness. The 12-40mm f/2.8 PRO is the faster-aperture alternative at greater weight.