Olympus's flagship super-telephoto prime with built-in IS, delivering 600mm equivalent on MFT.
The Olympus M.Zuiko Digital ED 300mm f/4 IS PRO was released in 2015 as the longest focal length lens in the Olympus PRO telephoto lineup, providing a 600mm full-frame equivalent reach at 1,270g — substantially lighter than full-frame 600mm primes at similar effective reach. The built-in optical IS cooperates with body IBIS through Dual IS 2 on compatible Olympus and Panasonic bodies for combined stabilisation. The lens accepts the Olympus MC-14 1.4x teleconverter, reaching 840mm equivalent. Weather and dust sealing is built throughout the PRO-tier construction.
The optical design uses 17 elements in 10 groups. Nine aperture blades produce smooth bokeh. The 77mm filter thread requires a large-format filter set. At 1,270g the lens is the heaviest in the Olympus MFT lineup. Minimum focus distance of 1.4m. Lens IS cooperates with body IBIS for Dual IS 2 on compatible bodies. Accepts the MC-14 1.4x teleconverter (reaching 840mm equivalent at f/5.6). Constant f/4 aperture. Weather and dust sealing requires pairing with a sealed OM-D body for full protection.
The 600mm equivalent at 1,270g is the defining practical argument: comparable 600mm reach in a full-frame interchangeable-lens system requires a prime or zoom weighing 3-5× more. For birds-in-flight, wildlife at distance, and field sports where reach at manageable weight is the primary constraint, the 300mm f/4 IS PRO enables handheld telephoto that would otherwise require a monopod or tripod. Combined Dual IS 2 stabilisation with a supported body enables handheld use at 600mm equivalent in outdoor conditions.
On the used market the M.Zuiko 300mm f/4 IS PRO is available at specialist MFT telephoto pricing. Condition checks: lens IS operation and Dual IS 2 cooperation with compatible bodies, weather sealing at the barrel and mount, front element for marks, and MC-14 teleconverter interface if the TC is included. The 77mm filter thread requires a dedicated large-format filter set. Compatible with all Micro Four Thirds bodies; Dual IS 2 full cooperation requires compatible Olympus/OM System or Panasonic bodies.