That in mind, it’s possible that the adaptation could spend as much as an entire act on Caladan – introducing the members of House Atreides, explaining the presence of the Bene Gesserit and engaging with the galactic politics.
If the film winds up clocking in around 150 minutes, it wouldn’t be too surprising at this point, given what we’ve seen, if it won’t be until 30-45 minutes in that the heroes arrive on Arrakis.
It’s been widely reported that Dune will actually only cover an undisclosed fraction of Frank Herbert’s book, and the great benefit of this is that it will allow the material to breathe and won’t be trimmed down to fit everything in.