I reviewed the new 5D Mark II back in October of 2008, and my decision back then was to wait until they’ve worked out the bugs. It looks like I did the right thing. I’ve been hearing quite a bit lately about focus issues with the camera. It looks like it can’t focus properly. It’s slow to focus, and when it does focus, the images are soft. See this blog post for an example.

I’m still not sure what lies at the root of the focusing problems. People are comparing photos taken with the 5D Mark II against photos taken with the original 5D, but it’s sort of like comparing apples to oranges. To compare images accurately, you’d need to first downsize the resolution of the images from the 5D Mark II to 12.8 megapixels, to make them equal in pixel depth to those that come out of the original 5D. I have yet to see something like that.

I think what’s going on here is that we’re seeing either the limitations of Canon’s 9-point AF system, or the limitations of their lenses, and this is due to the sensor’s increased megapixel count. In effect, all those extra megapixels have run ahead of the camera’s AF capabilities. It’s like a bodybuilder who’s got huge muscles but hasn’t trained his joints. His tendons have remained weak, and sooner or later he’ll tear something.

The thing is, I’m getting soft images with my original 5D, and I get them quite often. Sure, most of the images I get are in focus, but I bet you that if my 5D were able to output 21 megapixels of resolution, those same seemingly sharp images would be just as soft as those that come out of the 5D Mark II.

It could very well be that the 9-point AF system can’t focus properly. It’s just not that good, and its focusing limitations are seen quite well at higher resolutions. In that case, I have a feeling that the 16 megapixel images that one can get with the EOS 50D would also show some soft focus issues. They wouldn’t be as apparent as those found in the 5D Mark II, since there’s a bit of difference between 16 megapixels and 21 megapixels, but they should be there. It looks like some people are noticing a soft focus with the 50D, so there might be something to my theory.

On the other hand, it could be that my lenses, and the lenses of these people complaining about soft focus with the new 5D, need to be sent in for calibration. There certainly are tons of complains about soft images gotten with Canon lenses of all kinds — that’s nothing new. Who knows, if they and I got to send in our lenses, and they got properly re-calibrated by knowledgeable technicians, the images would be sharper.

So there you have it. I’m not sure what to think. I’m leaning toward the side that says the 9-point AF system needs to grow up, but I’m open to suggestions. Perhaps Canon ought to license the 11-point AF system from Olympus. They put it in their E-3 DSLR, which came out at the end of 2007. It’s supposed to be the fastest and most accurate AF system on the market, and it’s meant to work well even in low light. After all, let’s face it, both Canon and Nikon have borrowed the Live View concept from Olympus — they were the first to come out with it. Why not borrow the AF system as well?