Hi,

Can anybody reccomend a decent fisheye lens for the 5DMKIII for around £200-£400?

Thanks

If you want something cheap and will only shoot in bright light, consider the Zenitar 16mm. It needs to be stopped down to get any sharpness out of it.

Zenitar 16mm Fisheye (http://www.kenrockwell.com/zenit/zenitar-16mm.htm)

You can see it in action around 0:32 here:
6. Canon 5D Mark II Audio Exposed - Conclusions on Vimeo

If you shop around you should be able to find a used Canon 15mm F/2.8L for under £400.

Canon 15mm is a bit sharper, at least mine :), but Samyang 14mm is very good for $350, and has less barrel distortion

The Samyang 14mm is a rectilinear lens not a fisheye.

Any thoughts on the Sigma 15mm f/2.8 EX DG DIAGONAL FISHEYE? The reviews seem to be quite good.