Annoyed by having to tap the on-screen Shutter button to take a picture in the Camera app on your iPhone or iPad? Happily, there’s another way—press either of the physical Volume buttons on the side of the device to snap a photo. You can even press and hold a button to take a burst of photos. Be a little careful with an iPhone 6 or later, since it’s easy to press the Sleep/Wake button on the other side of the case accidentally, putting your iPhone to sleep instead of capturing that perfect shot.

Source: TidBITS