equivalent field of view and depth of field (DOF) as a 300mm f/4 lens on a full frame dSLR but with 2 stops more light yet more compact
this is an awesome nature photography lens
adding a EC-20 2x teleconverter gives a 35mm equivalent of a 600mm field of view yet effective aperture is only f/4 and easily hand holdable with the 4-5EV built-in IS of Olympus cameras.
specs
150mm focal length = 300mm field of view in 35mm terms
f/2.0-f/22
weatherproofed
11 Elements in 9 Groups, including ED/Super ED Lens Elements