DSLR and mirrorless camera setups have a habit of growing. Once you get beyond, say, a camera and a kit lens, an additional telephoto zoom and a flashgun, regular shoulder bags often run out of room. You can find yourself leaving bits of kit at home, inevitably missing something when a great photo opportunity presents itself. One solution is to buy a bigger shoulder bag, but it’s less than ideal. Carrying its full weight on one shoulder can be uncomfortable, and the strap may slide down your arm.