The Olympus M.Zuiko Digital ED 300mm f/4 IS PRO lens will be a game-changer for wildlife photographers. One may argue that this lens is for the Micro Four Thirds models only, whereas a lot of wildlife photographers use either full-frame or APS-C models. That is true. On the other hand, many are changing from the larger and heavier cameras to MFTs and a day will possibly come when the image quality from MFTs will be just as good as from their cousins using larger sensors. Another advantage is the weight of the lens (as well as the body). A 600mm prime lens for a full-frame sensor may be approximately 4000-5000g whereas the Olympus 300mm f/4 IS PRO is a mere 1475g! This further means that lugging heavy tripods may no longer be necessary (don’t forget that with compatible Olympus camera bodies, this lens offers six stop advantage in shutter speed). Hence, considering its marvelous performance, reasonable price, savings in weight and size, I fully endorse the Olympus M.Zuiko Digital ED 300mm f/4 IS PRO lens as ‘Best Buy’!