This was posted by David Gerrold on his web site (but it has been removed now):
I seriously doubt if they are filming in 70mm, though that would be cool. Maybe those were IMAX cameras.
Once we got onto the soundstage, we saw … a whole bunch of really neat stuff. Stage 18 is one of the largest on the Paramount lot (it’s where they shot the big crew scene in Star Trek: The Motion Picture) and the set that we saw totally filled it. We saw lots of computer screens, lasers, smoke, mirrors, machinery, bright lights, and big set thingies, plus a humongus thing that I’m not going to describe, but it took up a lot of space and must have been very heavy to hang from the rafters. We saw some very large cameras (they looked like 70mm cameras to me, but I could be wrong.) We saw a guy in what might have been a Starfleet uniform, it was very impressive and very very Star Trek. We also some some bad guys and they looked very good to me too, very much in keeping with the look and feel of classic Trek.
I seriously doubt if they are filming in 70mm, though that would be cool. Maybe those were IMAX cameras.