I have a Canon EOS 5D Mark III with a Canon 24-70 2.8 lens on it as my standard lens and then also a Canon 17-40 4.0 lens and the small Canon 50mm 1.8 prime lens with me. I am going to Japan on a holiday and I want to have a convenient bag or carrier, where I can quickly take out and put back my camera and not have too much hassle switching lenses. Before this I would have my stuff in a camera bag that was in my backpack and I would have to take everything out and back in for a single photo. Maybe something around the waist would be convenient. What's your advice?