To go backpacking I would have to add a sleeping pad and a sleeping bag. My sleeping bag is is 39 ounces and my sleeping pad is 14 ounces. Bottom line, if I want a base pack weight of 15 ounces or less I have to carry a smaller camera and or lens. Maybe the Nikon D40 with the kit lens. But I have a hard time with the idea of shelling out so much money just to save some weight on my camera.