I have fell mountain biking so many times and once our twice right on my back and all my stuff is good
i just slowly drift away from saying oh shit whenever i fall because i know all of my lens's, my camera, and my mic is good
http://www.dakine.com/p/packs/photo-packs/fall-winter-2013/mission-photo-25l?clr=002
and it holds everything
it also has a spot for your tripod or cam caddie/ opteka grip