Years ago when I was a young DP I spent £500 on a single day session to learn how to expose for low light. That was a lot of money then. At that session there were several DP's who are now working at the upper echelons of UK film and TV Drama. By the end of the day I had discovered that the answer to my question was: sure there are technical boundaries, but in the end there is no such thing as the correct exposure - because art is a gesture of the moment. A correct exposure in one moment is not the correct exposure in the next because the art or intention, or colour or texture of the scene.
The light meter and waveform monitor as used today for digital cinematography (and television back then) are two forms of evaluation, but these are just devices that allow a certain kind of ritual gesture to happen that produce a decision. If you're 'in the flow' when you make your decision, choosing a fat or thin f stop - or placing the exposure on the stop itself - then that decision, if made whilst transcending the form you're working in aligns with what artists do when they make their artistic gesture. That may sound airy-fairy but whether you're a street cleaner or an astronaut, we all operate in the same way - choices in the moment. So there's technical excellence on one hand and on the other, art - and if you're really aligning with 'the flow' or as Taoism would call it, 'The Way', then art can happen within commerce.
