A CHIP OVER YOUR SHOULDER
Until recently Nikon have worked hard to squeeze performance out of the CCD sensors. Eventually they gave up and moved across to the CMOS technology that Canon have been using all along. It was really a no-win situation for Nikon as the CCD chips use too much power and suffer from a range of undesirable side-effects because of it. But why did they back the CCD chips in the first place? Turns out that these chips are prefered by the Medium-Format units used in studio settings where power consumption, ISO range and long exposure considerations are less of an issue. In short, the CCD chips do produce better images given the ideal setting of a studio. Travel photographers and travellers in general however have more demanding needs, not the least of which are battery life and high ISO flexibility.
HOW DOS IT FEEL
Everytime I run a photo tour I meet a whole new bunch of people with strong views on what camera everyone else should be using. It's curious to me how some people say the Nikon is a more intuitive camera, it feels better in the palm and the controls are laid out better. The Canon users say exactly the same thing. It's down to personal preference for the most part, and often that personal preference is based on what you're familiar with. Once you invest in one brand you're very unlikely to migrate across to the other. Reality is that there is very little difference between one or the other in the same price range. There is a tendency for high end amateurs to buy Nikon, and for professionals to buy Canon. Beyond that the choice of brands is academic.
Unless of course you decide to buy an Olympus, Pentax or Sony! - The world of Digital SLR has become something of a two horse race even though many other brands have interesting cameras on the market too.
FASTER THAN A SPEEDING LENS
Canon led the charge in autofocus systems before Digital SLR technology became mainstream, and they got a few things right from the very start. Engines and mount rings. Nikon took the principle that if you put one focus motor into the camera body then you don't need an additional motor for every lens you own. It saves weight. Canon took the principle that every lens needs a different kind of motor, and very different motors to drive the autofocus on a heavy 600mm lens compared to a light and subtle 50mm lens. Eventually Nikon came around to join the mainstream and are now building cameras that only work with their newest lens range that have autofocus motors inside the lens jacket. Nikon's narrow mount ring is somewhat harder to work around and poses an engineering challenge to cram the projected image through a very tight ring.
What is important for people trying to decide between one brand or the other is that there is far greater differences within each range of lenses than between them. Canon make a few brilliant lenses, the 70-200mm IS for example was a leader in the press industry and gave them a clear advantage when trying to build market share. Nikon have caught up in most areas, and surpassed in others. But you have to know exactly which lens is the good one. That's why the internet is full of blogs, so photographers can debate the merits of individual lenses.
WOULD YOU LIKE VIDEO WITH THAT
The real battle ground between Nikon and Canon is the race to add features into their cameras. With high volume sales comes the ability for manufactures to add top end features into low end camera models. But at the professional end of the market the features list for new models is a technological challenge for the rivals. Adding video capture to an SLR camera might sound trivial, given most point-and-shoot cameras have that feature already. Maintaining quality of image for the stills while expanding the sensor capabilities is not easy. Any reduction of quality in colour response or dynamic range could be a disaster for sales and reputation.
Recently I had the chance to play with Canon's top of the line Digital SLR for a couple of months, while I waited for my less expensive 5D MkII to arrive at the shop. Canon sent me a loan unit for the 1Ds MkIII, which costs nearly three times the 5D MkII. It's a gorgeous camera, has an insanely accurate and quick focus screen (I thought my old gear was quick but it seems I was wrong), and it makes a sensuously smooth sound when you hit the shutter for a capture. It was divine. But it didn't have ISO expansion to 6400ASA and it didn't shoot HD video. It did have more subtle colour reproduction, it had a button to add voice annotations to your RAW files and the power grip was integral to the unit.
Eventually I got my 5D MkII and was happy to keep my spare dollars in the bank. I still sigh and reflect for a moment on that lovely few months when Canon shared their best technology with a simple travel photographer. The sweet muted clunk of a mirror bouncing out of the lens path is a fond memory indeed. It turns out that the ISO range of the cheaper model was the real winner however. I was sceptical at first about such a feature. If there's no light to shoot then there's no light to compose with either. Light is not just about volume, but character. Since then I have been proved wrong. Several assignments have placed me in rotten weather with silly deadlines, and I was able to salvage great images for publication using the extended abilities of the Canon 5D MkII.
The technology race between Nikon and Canon is driving genuine benefits for photographers, so regardless of which label you sling across your shoulder you're getting some good gear.