Hello Friend, its very tough to compare both the brands, as they both are equally good and have turnover of millions of dollars. It would be idiotic to make a comparison between them. Both Nikon and Canon makes lenses and camera body for commercial, military, space agencies from decades. $700 is a good budget and you will be able to get some best lenses, which are smooth and technically have good features. Just do some research over internet or by visiting their sites and you would get to know all the details. If you are a beginner then you can get good models in both the brands below 700$, go ahead and Good Luck!