Mr Chad:


Yes, 40D and 50D AI Servo is pretty bad. Even Galbraith said it just can't do the job at all.


I do however think that the 40D and 50D AF systems are faster and more accurate than the 5D2 in One-shot mode. Just based on the specs alone, it is only logical to conclude that, but I've read enough experiences for this as well.


Tom Alicoate:


The 5D2 is slower and less accurate compared to 40D/50D when you consider the outer AF points. That's not accetable in such an expensive pro body.


If there was a 15MP body with clean 12800 ISO, I'd pay good money for that, and I'd still get the 85mm f/1.2 L because that lens is simply incredible at f/1.2.


Steve Spencer:


I think that it's a fact that the 5D2 AF system is inferior to even the cheaper models out there, that it is slower and less accurate. There are enough experiences from others to prove this. Even just based on the specs, this is clear.


Based on those facts, my opinion is that it is a joke to include that kind of AF system in a high resolution camera where you would need a very good AF system to fully take advantage of 21MP. The AF system is very inadequate unless you stick to using center point alone. But this goes against one of the most basic rules in photography/art: the rule of thirds. Canon simply do not understand photography well enough, it appears to me.


Others may have their opinions on this and that again is fine by me.


With regards to cropping, I want to crop as less as possible. Otherwise you throw away a large part of 21MP. The whole point of 21MP is taking advantage of that resolution.With giving us this kind of resolution, Canon should also give us the tools to take good advantage of it, like a good AF system and AF points that are spread close enough to the rule of thirds grid.


Focus and recompose will not work, not for anyone, when using larger apertures. Try focus and recompose below f/2. Even smaller apertures are an issue depending on your subject. So this means that if you think you're going to be shooting wide open at a low light event and use focus recompose, you had better count on giving the client back their money and deal with a potential lawsuit.


Finally, I don't think the 5D2 is worth $2700 simply because it gives you less in a lot of areas compared to other cheaper systems from both Canon and Nikon. The only thing it has is 21MP, which are crippled because of the poor AF system, and which have artifacting issues right now. Is 21MP alone worth the price? I guess that is for everyone else to decide on their own. But it's not for me.