What 100-400mm at f/4.5 actually gives you
100-400mm is the classic portrait range — long enough to compress features flatteringly without forcing you across the room. On the APS-C bodies it covers, it frames like 150mm would on full-frame.
f/4.5 is a slow maximum aperture, so this leans on good light or on a stabilised body.
Size, close focus and filters
At 1375g (3.03 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 0.27x, enough for close-up work on flowers or detail shots without reaching genuine macro reproduction. It focuses as close as 175cm.
Filters are 77mm — 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 Linear 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.
