[Wavytone]

Now I now you all love your Canons but ... I'm just curious... has anyone tried a Foveon X3 sensor for colour imaging, presumably with a Sigma SD14 body ?

These things are not Bayer sensors - they have 3 layers recording RGB at every pixel, and the sensor is 20.7 x 13.8 mm, with 2460 x 1760 pixels so the pixels are about 8 microns.