If this information is correct:
http://www.imdb.com/title/tt3371366/technical?ref_=tt_dt_spec
...this film will have some moments that are shot on 16mm.
Why is that camera needed? I wonder what scenes they're using 16mm for...
One would make an assumption that Bay would be using 16mm for flashback scenes in WWII to give the film a certain feel from the day.
The film Carol was shot using the Arri 416 and it had a beautiful organic look which suited the 1950's period in which it was set.