Am I the only photographer in the M4/3 universe that needs a fast telephoto lens (400mm or 500mm f4)? All the current interest on mirrorless forums seems to be focussed on ultra fast pancake and sub 100mm lenses. Having experimented with M4/3 for the last 12 months, I finally sold all my Canon gear earlier this year and switched formats completely. However, as a wildlife photographer, I sorely miss my 500mm f4 and even my 180mm macro lens. The current 300mm lenses are just not powerful enough. For those of you who are searching for something bigger, it might be worth looking at the Kowa Prominar 500mm f5.6. It comes in at half the weight of my old 500mm f4, and splits into three sections for easy transporting. I have to say that I am really impressed with the resolution and image quality. The downside is that this is a manual only lens - for both focus and aperture. It also lacks image stabilisation. But until either Sigma or Panasonic (I think Olympus have more pressing issues) feel the need to produce a 'pro' telephoto lens, the Kowa is a reasonable substitute. The Great Tit was taken with the Kowa coupled with a GH2.