gotaudi wrote in post #11506737
Look at the 5D's autofocus progression (i know not too many data points to make a trend line) but both 5D's had the same autofocus system while the other canon cameras continues to progress. I think if canon does upgrade to a better autofocus system on the 5D mkIII it will move slightly. it will be more like what you see in the 40d and 50D.... not a huge upgrade but still it gives you something... I would be very surprised if they put the 7D autofocus system in there. I know canon wants to one up Nikons stuff but it also doesnt want to tread too much on its own toes (the 1D series)
I wouldn't say that every camera has progressed, at least not at each iteration. The 40D/50D/60D have basically the same AF system, and the 1D and 1D2/1D2n were the same. I know that they upgraded with the 20D over the 10D, and I'm not sure whether the 30D retained the 20D's scheme or was the first to have the 40D's scheme (they are different). Some of the older schemes have made their way to the Rebel series.
The 5D and 5D2 have shared essentially the same 15-point AF system (9 visible and 6 'expansion' points) for several years now, and it's drawing complaints from users due to the poor performance of the peripheral AF points. Additionally, competitors have superior systems and Canon's own lower-cost 7D has a system that is superior in most aspects. It would not be wise to fail to upgrade the 5D's AF in the Mk III version. People that have enough money to buy the 5-series are also people that have enough money to change systems, and both Nikon and Sony are waiting in the wings.
It has been my contention, with no basis in fact or inside knowledge, that Canon had intended to upgrade the AF system in the 5D Mk II, but halted that move due to the AF issues on the initial 1D3 bodies. My guess is that the new system, which was probably a lot like the 7D's system, was based on technology similar to that used on the 1D3 and that they didn't want to risk a faulty AF system on two high-dollar bodies. So, instead of upgrading and taking the risk, they maintained keeping the reliable, if somewhat dated system on the 5D2. Now that they've sorted out the 1D3's AF and have gotten things right with the 1D4 and 7D, they are free to upgrade in the next 5-series model.