Don't know if this been has posted before, but I found it quite interesting.David Keighley (Head of Re-Mastering IMAX) Talks THE DARK KNIGHT, THE DARK KNIGHT RISES, TRON: LEGACY, New Cameras, More
Interview with Christopher Nolan:The Traditionalist
The Dark Knight: Post in 35mm and IMAX
Q: You and your cameraman, Wally Pfister, are—along with Steven Spielberg—among the last holdouts who shoot on film in an industry that’s moved to digital. What’s your attraction to the older medium?
A: For the last 10 years, I've felt increasing pressure to stop shooting film and start shooting video, but I've never understood why. It's cheaper to work on film, it's far better looking, it’s the technology that's been known and understood for a hundred years, and it's extremely reliable. I think, truthfully, it boils down to the economic interest of manufacturers and [a production] industry that makes more money through change rather than through maintaining the status quo. We save a lot of money shooting on film and projecting film and not doing digital intermediates. In fact, I've never done a digital intermediate. Photochemically, you can time film with a good timer in three or four passes, which takes about 12 to 14 hours as opposed to seven or eight weeks in a DI suite. That’s the way everyone was doing it 10 years ago, and I've just carried on making films in the way that works best and waiting until there’s a good reason to change. But I haven't seen that reason yet.
Edited by Buurke - 11/15/12 at 2:21pm
Shooting on IMAX posed some serious postproduction issues, too. Smith continued, "Chris really likes the look of film and the photochemical finishing process instead of a DI, so our post followed the traditional route—except for the IMAX negative, of course. Our goal was to keep the IMAX in its native format for the IMAX screenings. For the 35mm prints, the IMAX shots were digitally scanned and recorded to 35mm negative that was cut together with the 35mm camera negative. IMAX does this by scanning their 65mm negative at 8K resolution. Effects within the IMAX scenes were handled at 8K as well. These shots were then reduced to 4K resolution and recorded out to 35mm film.
"You also have to go in the other direction for the IMAX release. For these, the cut 35mm negative was color-timed at the lab [instead of a DI], producing an interpositive of the 35mm portions of the film. This went to IMAX, who used DMR—an IMAX-proprietary digital process—to 'blow up' the 35mm to the IMAX format. These scenes were then intercut with the IMAX camera negative. So, digital processes were used for the two format conversions, but each set of release prints was created by cutting the negative and timing the shots in a traditional manner."