I'm wondering why Canon chose a 22MP sensor for the 5D MkIII; there was talk of 22MP being a 'magic number' for pixel binning to 1080p video, but I haven't seen any evidence of this in Canon's specifications for the camera? Have I missed it, is it absent or are they planning to implement it in a firmware upgrade?
If there was no intention of pixel binning to acheive 1080p video, why did Canon choose 22MP for the 5D MkIII's sensor? Surely they should have either used the 18MP sensor from the 1D X, or if they wanted to protect 1D X sales, gone for a slightly higher number for marketing reason if nothing else. I can't help thinking that 24MP or 25MP would have sounded a lot better from a marketing standpoint (even if unnoticable).