It's not small!!
However, just imagine what a 200-600mm 'Full-Frame' or a 135-400mm APS-C lens + built-in IS would look like and of course feel like to carry around. While it looks huge this lens is actually pretty light for what it is. And somewhat surprisingly produces pretty sharp files.
I bought it initially for shooting 4K video with, but have used it for stills and am very impressed. I've actually never owned a lens this long, in any format, so this is proving to be an interesting experience. I have no real need for this kind of 'pull' but I'm finding it lets me explore the possibilities of extreme telephoto and the different kind of images that can produce. It's not especially fast, but with the OIS and upping the ISO a bit, I can get pretty impressive landscape and nature shots. One of my favourite landscape photographers - COLIN BAXTER - uses a lot of telephoto lenses and I've always wanted to try that approach. However, I've always been put off by the size and weight. But with m4/3 I can finally give it a try.
Here's what it can do.