What 300mm at f/4 actually gives you
300mm is genuine long-telephoto reach, with the strong compression and narrow angle of view that comes with it. On the Micro Four Thirds bodies it covers, it frames like 600mm would on full-frame.
f/4 is a moderate maximum aperture. There is less low-light headroom and less background blur than an f/2.8 lens gives, which is generally the trade for lower weight and cost.
Size, close focus and filters
At 1475g (3.25 lb) this is a lens you plan around — it wants a larger body to balance against, and a tripod collar or monopod for extended use. A tripod collar is included, which moves the mounting point to the lens's centre of mass rather than hanging the weight off the camera's tripod thread.
Maximum magnification is 0.48x, enough for close-up work on flowers or detail shots without reaching genuine macro reproduction. It focuses as close as 200cm.
Filters are 72mm — worth checking against what you already own, since polarisers and ND filters at this size are reusable across any other lens sharing the thread.
Autofocus, stabilisation and weather sealing
Autofocus is driven by a DSP motor.
Optical stabilisation is built in, which stacks with in-body stabilisation on bodies that have it and does the work alone on bodies that do not.
The barrel is weather-sealed, so rain and dust are a manageable risk rather than a reason to pack up.
