I recently stumbled upon a useful tool in Cinema 4D on how to keep cameras (or any object for that matter) locked in the same position.Quite often I mistakenly moved my camera in the viewer window, and Cinema 4D doesn’t allow you to revert back to the view you just had, so essentially your perhaps perfect camera angle is gone. One solution was to add only one set of keyframes to the position values at a specific frame. But their has to be another way…. 

And there is. I stumbled upon the “Protection” tag in the Cinema 4D tags menu.

So in the Object Manager ->Tags -> Cinema 4D Tags -> Protection. It will lock the position and rotation of your camera, or any other object, but not the more specific object settings.