You will want to wipe the cache of the camera app. Make certain that the camera lenses area clean.... using a micro fiber cloth. Unless you have have altered the camera settings, you should be getting stellar pics. If all else fails, a factory reset will set everything back to factory fresh including the camera settings. If you do a factory reset, be certain to back up everything for they will be wiped from the phone. If the factory reset is not the answer, it's likely that you are experiencing a hardware problem of some sort.