[E. von Hoegh]

We have wind up radios, as endorsed by Nelson Mandela, so why not a wind up light meter?

As I pointed out above, clockwork cannot by it's nature measure light. The wind up radios use the machanism I described above, or have no clockwork and the user turns the generator directly by a small crank. The actual radio is no different from any other radio deriving it's power from a chemical battery, photovoltaic battery, or mains voltage.