There aren't currently many choices in the ultra-telephoto category for micro four-thirds, and without having tested the Panasonic 100-300mm, it's hard to recommend the one over the other. Optically the Olympus 75-300mm does very well, but not where you'd want it to - it's super-sharp at 70mm, not at the 300mm where I suspect the grand majority of users will want to use this lens. At 300mm, it's only above average, there's noticeable chromatic aberration, and the maximum aperture of /6.7 is one of the slowest I've seen for SLR lenses (even Tamron and Sigma seem to draw the line at /6.3). Read full review ...
There aren't currently many choices in the ultra-telephoto category for micro four-thirds, and without having tested the Panasonic 100-300mm, it's hard to recommend the one over the other. Optically the Olympus 75-300mm does very well, but not where you'd want it to - it's super-sharp at 70mm,...
