The camera click noise is a digital sound effect of a camera shutter clicking when a photo is taken on the Apple iPhone. This clicking noise is heard anytime a picture is taken with the built-in camera.
To temporarily stop the noise slide the bar of the phone so that the orange colour tab is showing. This will place the phone in silent mode and silence all sound effects including the camera click. This will also silence the ringer and notification sounds. However, another method is available.
Open iTunes on your computer and go to the Apps Store link. Download the application called "MobileFinder."
Connect your iPhone to your computer via USB cable. You will be prompted to update the iPhone and install the latest app.
Go into applications on the iPhone and run the MobileFinder application. Locate the "System/Library/Audio/UISounds" folder. This folder contains all the default sound effects loaded into the system.
Scroll down until you find "photoShutter.caf." Double-click on the file and click once on the "filename" setting. Change the file name to something else. The change could be as minor as removing the "r" in the word shutter.
Exit MobileFinder and try to take a picture. The clicking sound should no longer occur.
Later versions of the iPhone software may eventually include a user friendly way of turning off and on the camera clicking sound. Check your iPhone settings before using this file changing method.
Changing file names may cause operating issues, and third-party applications may not always work as expected. There is no guarantee that this method will work on all versions of the iPhone.