E6 is not particularly easy to buy or process (especially if it’s fast enough for movies), which makes me think he’s talking about regular C41 print film. That would rule out the possibility of projecting the film he shoots – he’d have to scan the negatives to invert them.
I would have naïvely assumed that it was cheaper to use real movie film, as that is at least still a thing (just). I’m sure it’s expensive, but unless he cut a special deal, he must be spending north of $10 per second as it is.
