It depends. Being unwilling to pay $$$ for a real camera bag, if I'm going for a hike more than a mile or two away from the car I stuff my Zone VI, three lenses, meter, focusing cloth, etc. into a standard sport-type backpack. I can either fit a couple of film holders into the bag, or can carry more (up to nine) in a seperate cooler bag (the insulated sort of bag sold to carry one's lunch, or a six-pack packed in ice.) If I'm closer to the car I just keep the camera & etc. in the (larger) insulated cooler bag I normally store it in. Camera, up to nine film holders, three or four lenses, etc. They work very well, I think. I have a system - red bags are 4x5, blue are 8x10. The same backpack works for both.

Mike