I think any photographer has encountered in one point of another "that guy/girl" that takes a look at your camera, frowns and then says "oh I'm a Nikon/Canon". This simply bothers me.
Canon and Nikon are fantastic camera makers that produce top of the line equipment and most professional photographers today would use any of these brands. To make it very clear, owning a Nikon/Canon camera will not automatically make your pictures better nor owning a $3,000 DSLR (this is a discussion for another day) will make you a better photographer. A good picture relies on the skill of the person behind the camera and how well you know the equipment.
Why choosing a brand over the other?
The truth behind choosing one brand over the other relies mostly on personal preference. For me, the first DSRL I ever held in my hands was the Canon 40D you see in the picture and it was my company's camera. When the time came for me to buy my very own DSLR, it took me a while to figure out what way I should go. I tried as many cameras as I could, saw what felt right and I was about to buy a Nikon D7000 but one very important thought crossed my mind: "I have a lot more Canon gear available to me than Nikon".
This was a decisive factor for me because as a starting photographer one of the hardest parts is building your equipment, buying lenses and speedlites can get very expensive. Unless you are filthy rich this a process that takes time.
This is my story but when you usually go to a camera store and ask the sales reps what's better Nikon or Canon? They are going to say: "it's up to you, whatever camera you like better" unless you go to best buy or future shop (not my fave camera shops).
What are the main differences between both brands?
The differences are actually on a technical level and are not that noticeable, so if you are an amateur or an intermediate photographer, this shouldn't really matter to you. It only matters when you are actually working and taking pictures for a living, certain specific camera features or tech specs might help your work and suit your shooting style.
Just to name a few :
- Vibrant colours vs neutral colours
- Camera mount compatibility
- Flash exposure compensation mode
- Nikkor lenses vs L series lenses
- Off camera flash system
Hope this post helps you see that a picture taken with a Nikon or Canon is not better or worse. Choose a camera that suits your budget, style and skill level regardless of the brand. The end result is only limited by your creativity, not a camera maker.