Manual advantage

Another advantage of using manual mode, says Nigel, is that once you’ve set your exposure you can recompose a shot without the changed composition affecting your settings. In shutterpriority mode your camera will adjust the aperture based on what’s in the frame – so a bright waterfall or sky will give a different reading from dark rocks, which might result in underexposure (see below). In manual mode the settings will stay the same no matter what you’re pointing at, ensuring a correct exposure.