Mads Nissen, using Canon equipment, won the 2014 World Press Photographer award.
Hastalosmegapixeles put together an interesting graphic showing the breakdown of cameras used by press photographers for the World Press Photo 2014 awards. There are few surprises here. Canon is clearly preferred by the majority of users, who used predominantly DSLR cameras.
The Canon EOS- 1D X is the clear favorite, followed by the EOS-5D MK II and Mk III cameras. Nikon made a good showing with their D4, D700 and D800 DSLR bodies but came in a distant second. The remaining camera models came from manufacturers such as Canon, Nikon, Sony, Leica, and Mamiya.
Overall, Canon is the preferred equipment used by 58% of the photographers, followed by Nikon with 28%, Leica at 7%, Sony at 5% and Mamiya with 2%. The remainder are divided into various manufacturers, medium and formats. There are a small number of medium format and film camera users in the statistics as well.
My own observation is there are many things that contribute to a great photo. First and foremost is the perfect chance encounter. The old adage of 'the right time and the right place' is never truer. Then comes the skill and experience of the photographer. Next comes the quality and capability of the camera equipment.