Image courtesy: Robin Wong
Robin Wong (click here) tested the new Olympus 300mm lens and writes:
Using the M.Zuiko 300mm F4 PRO lens was quite an eye-opening experience as the thrill and awe I went through reviewing the image quality produced by this lens. There is not much to write about what I dislike. Here is the sharpest lens Olympus has ever manufactured, and adding to that the introduction of even more powerful version of the already incredible 5-Axis IS system.This may not be the lens for every one (certainly not me), but if you do find a need for a 300mm lens in your type of photography, I think the 300mm is the answer to your prayers.