New Photo shooting of Golshifteh Farahani behind the scene of a movie

Wave forms are a great way of measuring the overall exposure, and can also be used to see the colour balance (use vector scopes for even more accurate control), the waveform display gives you a spread out chart informing you of the different layers of IRE in your image. For best control you don’t want anything crushed down the bottom or flat up the top; it is always best to make creative choices in post-production.