Hi,
I think you are facing a commong issue. you need to have your camera or the actual yobject that follows your player to use "LateUpdate" instead "update", else you will always get jittering, because the rendering engine is out of synch with your code ( it's a known fact when using physics objects)
Can you tell me more about your camera prefab setup and what technic /actions you use to follow your player?
bye,
Jean