Canon EOS-1D Mark IV Autofocus vs Nikon D3s

Rob Galbraith, a well-known and respected photographer from Canada, has recently posted an article on autofocus performance of the new Canon EOS-1D Mark IV after using the camera for a while photographing various athletes that were preparing for the Vancouver 2010 Olympics. After weeks of shooting the camera, he compared the autofocus performance of the Canon EOS-1D Mark IV with the new Nikon D3s.

Here is a quick excerpt from his article:

It's worth noting one other fundamental difference between the AF system in the D3S and that of the EOS-1D Mark IV. When Nikon focus is out, it doesn't tend to be way out. More often than not, peak action frames that are not perfectly focused aren't that blurry, making some of them still viable. That is, if you're of a mind that it's better to have a slightly soft frame of a great peak moment than a totally blurry one. The EOS-1D Mark IV, on the other hand, produces many more frames that are too soft to use for anything, no matter how sweet the moment.

To sum up, our experience with the D3S' AF system is that it's trustworthy and dependable enough for us to be confident using it for peak action sports. Not perfect: it needs to be a bit faster off the line, in addition to the other quibbles we've mentioned. But it does work as needed most of the time, which is in stark contrast to the experience of the EOS-1D Mark IV in the last month.

The above review is pretty much in line with what many other sports and action photographers have said after doing comparisons between the two cameras - the Nikon D3s is currently, without a doubt, a leader in both autofocus and low-light photography (high ISO performance).

When I looked at some sample pictures of the Canon EOS 1D Mark IV, I got a little worried about Nikon D3s future. However, after seeing some high ISO comparisons and hearing from pros on autofocus performance of both cameras, it turned out that D3s is the leader and it looks like it will stay that way for at least another two years! Sure, it is unfair to compare Nikon's full frame sensor with a 1.3x cropped sensor, but poor autofocus performance has been Canon's biggest weakness (especially in 1D Mark III) and despite the fact that Canon re-engineered their autofocus system from scratch in 1D Mark IV, it is still worse than Nikon's legendary 51 point autofocus system.

Nikon D3s wins, end of story.