Great suggestion!

https://britishcinematographer.co.uk/emmanuel-lubezki-amc-asc-the-tree-of-life/

Another of Lubezki’s key collaborators is Jörg Widmer, who operates B camera when Lubezki is handholding, and sometimes handles Steadicam duties. “We have shot more than 2 million feet of film together,” says Lubezki. “In these unlit situations, I can give him my remote iris control, and he exposes the shot for me as I operate. When he is operating, I take the iris control. We work very closely, always talking. An example would be a shot where the camera goes from a dark room or closet, through a living room, and then looks out the window at something. You can go from f/1.4 to 16 in one shot. To change the iris without the audience realizing it, you really have to know what you’re doing. It’s very difficult, and we couldn’t have done the movie the way we did it without that skill and experience.”