Brian Ach has shot for just about every big-name publication you can think of. Rolling Stone, The New York Times, People and Time are all on his resume, and he's photographed his share of A-list celebrities, including a stint as Prince's official tour photographer. In short, he knows how to get the shot. But he argues there's an important distinction between getting shot and getting the right shot, and it all comes down to context. 

Take a look below at his PIX 2015 keynote in which he discusses his take on what makes a great shot, and click the gallery above for more detailed information about a sample of Ach's portfolio.