Canon or Nikon ?
When somebody starts to get serious about photography, this is a usual question to answer. Why this two brands ? Because they have the most and best quality to offer:lenses, acessories, flash units. Other brands like Pentax, Sony are not really able compete with them especially in the Professional market. If we check the professional photographers at least 95 percent of them uses these two systems. When we think about such a question we compare not just the cameras, but the lenses, and accessories as well. Or I would say for me the lenses are more important, than camera bodies. Why? One can make an excellent picture with a really good lens and a cheapest Dsrl camera, but never can make the same with the most expensive professional Dsrl camera with a bad or mediocre lens attached.
The good lens is can be better even with an extender(optical magnificator) attached than a mediocre lens without extender. What output come out of your lens, no DSRL camera make it better afterwards. When we speak about cameras, we can speak about consumer, prosumer, or professional models. Both company has all kinds of cameras. When we compare two cameras, for example, we should compare apple to apple, means consumer camera to a consumer camera, or pro camera to a pro camera. If we compare for example lenses, we compare a pro lens to a pro lens. For example a Canon 300/2,8 is lens compare to a Nikon 300/2,8 Vr lens is a fair comparison. Most serious photographers uses these two kinds of cameras. Both companies has excellent cameras and lenses. The preference between these companies is a personal decision. If someone likes telephoto photography and not a millionare I would suggest Canon, for wide angle/landscape photography perhaps suggest Nikon. If someone a millionaire, and wants the best out of photography I would suggest to buy the best lenses and cameras from Canon and Nikon as well :). What are these: Canon 500 f4 is MkI, or even Mk II, Nikon 14 24 f2.8, Nikon 400 f2.8 Canon 135 f2, Canon 300 f2.8 is Nikon D800 camera just to name a few. Both companies has excellent pro telephoto lenses. If someone has not so many resources there are many good lenses or cameras for smaller amount of money, like: Nikon 35/1.8, Canon 200 f2.8, 85 1.8, etc. The Tamron 17 50 is a very good value lens available in both systems, although not fabricated by Canon or Nikon can be attached to either if we buy the appropriate product. This lens made excusively for Aps-C cameras.
Nikon has an advantage in camera bodies recently in dynamic range, over Canon. Doesn’t mean that is always be like this. Canon’s top of the line lenses are usually cheaper than Nikon’s. Canon is very strong in telephoto line-up, Nikon has an excellent 14-24/2,8 wide angle lens, and generally Nikon is stronger in wide angle lenses. Nikon consumer wider zoom range lenses are cheaper and better, than Canon’s. Nikon lenses can mount on Canon cameras(with only manual focusing), but Canon lenses usually cannot mount on Nikon cameras (Canon’s camera-lens distance is smaller). My opinion is that easier to buy or sell a Canon camera/lens on a used market than a Nikon camera/lens, because much more available and more people has Canon system.