Wednesday, August 01, 2012

A Guide To 70mm: Part Three

Ever since we first heard that PTA would be shooting “The Master” (at least partially) in 70mm, we’ve gotten a lot of questions on what exactly that means for the film. We spoke to Datasat Vice President Daniel Schulz (who worked with PTA's team and The Weinstein Co. on mastering the 70mm sound for the film) to get all the answers you might need. 

In years past, 70mm was played back using magnetic striping on the print itself; in fact, one of the major advantages of 70mm was that the increased physical size of the film meant you could include up to 6 discrete tracks of magnetic sound, rather than 2 or 4 as was common with 35mm.  So, the first releases with fancy mixes such as 5 screen channels plus surrounds, or early 5.1 style soundtracks, were always done with 70mm.  Even after the waning of the great era of 70mm, studio pictures that were shot and released mostly on 35mm would have 70mm blowups made for the premiere and coastal cities, in part because of the better soundtrack achievable with 6-channel sound.

That era began to wane with the advent of Dolby Stereo in 1977 with Star Wars, which enabled low-cost, high quality 4-track sound with optical tracks on the 35mm film (mag striping is expensive and technically tricky).  Things really came to head in 1993, when DTS launched with Jurassic Park, enabling superb quality 5.1 digital sound with 35mm film.  Dolby countered with Dolby Digital, also playing back 5.1 digital tracks read off the 35mm film print.  This meant studios could provide superb surround sound tracks in a digital format, with 35mm film prints, eliminating one more reason why 70mm was preferred for high profile screenings, and in fact Dolby used this as one of their marketing reasons for studios to adopt Dolby Digital.

The DTS system was film-size agnostic: it plays back from a CD-ROM, synchronized to the film print using a timecode track printed on the film.  From the very beginning, DTS adapted their system to print timecode on both 35mm and 70mm film, and manufactured readers to read timecode from either film gauge.  Meanwhile, Dolby never did engineer a 70mm version of Dolby Digital.

Fast forwarding to today, there are no labs left that can do mag striping: the process was environmentally troublesome, and as demand fell off to zero the equipment fell out of use.  Fortunately, DTS has kept the torch alive, and has been instrumental in providing soundtracks for a whole host of 70mm restorations done by the major studios and the Academy Film Archive.  In 2008, DTS sold their movie business to a company called Datasat, but under the re-branded name of Datasat Digital Sound, we have continued to support digital surround sound for both 35mm (pretty much all Hollywood movies come with Datasat Digital Sound tracks for the 35mm prints) as well as 70mm restoration work.  Some of the titles that have been exhibited in 70mm with Datasat sound are Lawrence of Arabia, Spartacus, The Sound of Music, 2001: A Space Odyssey and Baraka.

All of which is to say, when PTA decided he wanted his masterpiece exhibited in 70mm, Datasat was an integral part of that process, as we did the digital soundtrack encoding and have been providing technical support to all the venues playing the film in 70mm.  As you know from your process of documenting the 70mm projection side of things, there was a bit of a scramble to ensure that venues had the correct equipment, in good working order.  In our case, most of them had the necessary DTS or Datasat playback unit (since DTS was a pretty widely adopted format, with nearly 20,000 theaters in the US equipped with DTS players since 1993), but needed to be supplied with 70mm timecode readers.

Since Datasat is highest quality digital sound format available for film (due to its low data compression), it is a perfect match for the stunning visuals of 70mm.  We're proud to have been able to help Paul realize his vision with a soundtrack as compelling as his images.

Read Part One
Read Part Two

You can find out more information on Datasat Digital Entertainment on their site.


  1. Great piece!! nice to learn more about 70mm and the technical side of things and also to learn about the diff betweeen Dolby and DTS/Datasat...

  2. Agreed. Great piece. Very informative.