Pocket-Lint: Buy a battery grip for your professional or semi pro digital SLR and it will come with a second set of essential controls to one side near the base, including an additional shutter-release button. That’s because grip and body make for a big and bulky bit of kit, so dual controls ease what would otherwise be an awkward stretch for the fingers if turning the pro DSLR on its side to shoot vertically, or "portrait fashion".
