I use the Olympus OMD em1-x as my main bird photography camera. I recently bought a used Olympus 100-400 for it, the lens came from eBay and I got it for £456 which is a very good price! The lens has proved to be absolutely sharp and some copies aren't like this. Here are some shots from it
I took some time out to walk around my village here in Haddenham. I often go out for "birding" walks as I call them, I have studied the locality and behaviour of the local bird life. This has helped with the shot of the Blue Tit as I was waiting for one to alight just where he sat so this worked well I have been doing images lately with my Olympus OMD EM1-X and an old 50-200 Olympus lens with the 1.4 converter which gives a real magnification of 585mm a good birding lens