i think you will find the lights dimmed for take-off a bit of a furphy.
the debate will never cease (nor should it), but lights dimmed for take-off at most airlines is a marketing department concept to give fare paying pax a better squizz outside. it is often sold as letting the eyes getting accustomed to the night/outside light but thats a bit of a laugh really when a) it takes a fair while for it to take effect, b) the lights in the cabin arent that dim in many airlines, c) everyone turns their reading lights on