The Canon 1D Mark III has become my new workhorse. It has all but completely replaced the Canon 5D I was previously shooting with, proving to me every time it is worth the extra weight and drop of 2 megapixels. Even though the 5D still produces superb high quality images, the 1D matches it in good light and is able to go that extra mile at high ISO settings. Likely along with the Nikon D3, it represents the best in low light shooting image quality. In normal conditions, its Highlight tone priority ensures that highlights are preserved exceptionally well and this, along with its handling, build quality and feature set ensures its versatility extends to far beyond sports.

As for the much discussed AF system, when combined with capable lenses and for the subjects I shoot, I’ve yet to see better than the 1D Mark III. Using Single Focus, in all conditions, it’s actually hard to imagine it being better.

In bright sunlight using AI Servo, I’ve seen it produce excellent images the majority of the time. When you factor in the increased frame rate and deeper buffer it’s capable of producing more in-focus frames over a sustained burst than its predecessor, the 1D Mark IIn. However, there is definitely still room for improvement as "good" but not exceptional is how I would describe its performance in these conditions. You can get "excellent", but it requires you stop down the aperture and whether that’s possible depends on your subject and intended goal. So, the question may be is whether "good" is indeed good enough for Canon’s premier sports camera? Well, if you’re shooting exclusively in bright sunlight conditions, I’ll state the obvious and that is you probably need to factor this decision in with other aspects that are important for you. For me however, AI Servo in bright sunlight represents less than 5% of my photography. After seeing the results that the camera already produces wide open and the excellent results when stopped down, I barely flinched. It’s already as much as I need.

You see, when the light starts to drop, thats when the options for workarounds start to run out and fortunately, this is exactly when the camera starts to raise the bar. Shooting in AI Servo in cloudy or overcast conditions produces excellent results all the time and stopping down allows the camera to produce near perfect results in the right hands. In low light (indoor / outdoor) conditions the 1D truly flexes its muscles and delivers on the promises that the marketing brochures make. As I said, if there’s a combination other than the 1D Mark III and the Canon telephoto primes that is better for indoor sports, I’ll be both very surprised and very impressed.

I’ve not had the opportunity to shoot properly with a Nikon D3 so I can’t make any in depth comparisons other than on paper but after handling one a few times, seeing many samples and talking to several owners, I’ve seen nothing to suggest that either has a significant advantage over the other when it comes to real world results. At the level they’re both competing at, differences in skill of the photographer and suitability of the system to those skills (lenses, flash, etc) make a far bigger impact than the odd frame here or there. This is great news for photographers from any so-called camp.

Two final words to caveat however. The first is that my own testing has all been done on a single body. I’ve not had an opportunity to replicate it with other 1D Mark III’s, so there is no guarantee that you’re experience will be the same as mine. The second thing to bear in mind is that the 1D Mark III is a complex beast. From having to adjust to a new AF point selection method, to learning the finer aspects of a new AF system, to having to micro adjust all my lenses, getting the best performance from the camera took some trial and error and definitely an investment of time. The results can absolutely be obtained, but they do require some effort. Perhaps to some, it might even be argued this makes it even more rewarding.

So finally, in conclusion, for what (and how) I shoot, with the 21MP 1Ds Mark III as the only possible exception (and only then for certain types of photography), the 1D Mark III is the best body that Canon have ever made, which in turn makes it one of the best cameras ever made.