Apple iPhone iOS 8.1 - Manual (Page 92)

Chapter 12 Camera 92
Camera settings
Go to Settings > Photos & Camera for camera options, which include:
iCloud Photo Library beta, My Photo Stream, and iCloud Photo Sharing
Burst photos
Slideshow
Grid
HDR
Adjust the volume of the shutter sound with the Ringer and Alerts settings in Settings > Sounds.
Or mute the sound using the Ring/Silent switch. (In some countries, muting is disabled.)