Share your experience!
Do you experience the same lag while on safe mode?
settings > apps > all > camera > clear data > boot on safe mode again > check again.
You have to find the app that its causing this, its not a preloaded app, it's an app that you've downloaded, it could be a taskiller, antivirus, ram app, battery app, etc.
What I do is this
open the app drawer > swipe left to right > installed > swipe left to right > uninstall > uninstall app by app until you find the culprit