Then on to the 1D3 -- I've aspired to master the combination of the 100-400 lens and the 1.4x TC -- giving a "widest" aperture of f/8, which is quite slow for wildlife, but fortunately the light was decent an I mostly used f/11 and ISO 800 to a thousand and had OK shutter speeds. I could have and should have upped the ISO to 1600, though