You turn it ON or OFF when the Camera app is open. If you switched it to OFF, then the next time you open the iPhone camera app, it defaults to OFF (which is what you had it set the last time you used the Camera).
You turn it ON or OFF when the Camera app is open. If you switched it to OFF, then the next time you open the iPhone camera app, it defaults to OFF (which is what you had it set the last time you used the Camera).