Part One: Film Preservation In The Advent of Digital Media

Cannes Film Festival

Stock Footage


There’s no question that film is a record of history.  There is also no question that the lessons of history need to be accurately preserved so they are accessible to future generations.  The complexity of accurately preserving film stock and digital formats is the focus of Academy of Arts and Sciences’ Head of Film Archives Mike Pogorzelski.

“There certainly are established storage conditions that will extend a roll of a film’s life as long as possible,” said Pogorzelski.  “There are some debates about how cold is cold enough, how dry is dry enough, but generally speaking, it is accepted that film is happiest in a cool and somewhat dry place.  Everyone with large film libraries should have temperature and humidity controlled vaults that they store their films in.”

There are three types of film stock that have been used over the first one hundred years of cinema.  The first stock, nitrate, was used from film’s birth until the 1950s.  It was made out of nitro-cellulose and was extremely flammable.  During the burning process the chemical reaction of nitrate creates oxygen, allowing a flame to continue burning even under water.   Pogorzelski explains that much of silent film history was lost not only due to fire but to a lack of appreciation for film history at that moment.

“Most people in the teens through the 30s didn’t see an economic or cultural value in the silent films,” said Pogorzelski.  “It was a liability to store them, especially a lot of them in a single warehouse, because there were nitrate fires all the time.  The loss of life and the loss of property was always a big concern.  That’s why a lot of silent films are no longer with us.”

From the 1950s until the 1990s “safety films,” which had an acetate base, were used.  Although this film stock was less flammable and safer to handle, it fell prey to “vinegar syndrome” as it deteriorated.  

“When safety film deteriorates it gives off this very vinegary smell,” said Pogorzelski.  “Unfortunately, that is also an auto-catalytic reaction.  Once the tape role starts disintegrating, you can slow down the process but you can’t stop or reverse it.  So it’s very important to keep acetate films in cold vaults, because that seems to help keep them from beginning to deteriorate.”

Films made with the acetate stock are being lost due to deterioration and color fading.  Color fading is the largest issue facing these films, primarily Eastman color film.  This film used a single color strip process consisting of three dye layers.  The color fading passes systematically through the dye layers until it reaches the third, or red layer, leaving the entire image in a red hue.

"Luckily there are ways to preserve color in Eastman film by making a black and white copy of each of those dye layers," said Pogrzelski.  "Black and white won’t fade over time. You can still go back to the black and white separation masters, as they’re known, bring all three of those records together and you’ll have the complete color spectrum."

Since the 1990s a polyester based film stock has been used that appears to be resilient and has not shown any signs of deteriorating like nitrate and acetate films.  Over the last several years, digital technology has become utilized in most every form of filmmaking from short subjects to features.  Although preservationists have determined general methods of safely storing film, archiving and preserving digital matter has become a complicated and under-explored matter.  One must first understand the digital process.

"If you shoot with a digital camera or if you shoot with film, all of the images are either scanned or ingested into some type of digital workflow system.  That’s where all of the color correction and visual and optical effects take place," said Pogorzelski.  "The film that ran through the camera is not the ‘original’ anymore.  Let’s say that a director is working on a film and decides that she wants a close-up to be a little tighter on someone’s face: that’s very easy to do in the digital realm, you basically just change the framing using digital tools".


The challenge digital recordings present to archivists is to determine what footage is important to save. 


"From a preservation standpoint, the director’s final framing is the final work, but the camera negative, the film that went through the camera, reflects the original framing.  How useful is that, and should that be preserved at all, since that was changed in the digital realm?" questions Pogorzelski.  "Changes like that are made all the time, especially in terms of film’s final color balance.  Archiving that data is where the challenges lie."

Further complicating the digital arena is the fact that technology changes at such a rapid pace. There is no one who can ensure that files created now can be deciphered in the future.

"The first digital intermediaries were primarily used in Europe in the 90s," said Pogorzelski.  "Those files, made in the mid 90s, are completely unreadable, because the vendors went out of business, or they were using some sort of proprietary file format.  A custom directory system that informs the operating systems how the files or data are arranged, can’t be used without doing a lot of archeology in a sense to try to figure out what those files mean.  In the meantime, the 35mm recorded negative is now the defacto original because the digital data is, in effect, unusable."

The Academy’s  Science and Technology council is currently working on a project in partnership with "Preserving Creative America," a grant program overseen by the Library of Congress, to develop a digital archive that would be able to house a moderate amount of born digital data.  Their hope is to develop a model that other institutions, universities and libraries with collections in the 20-40 terabyte range would be able to adopt. 

Coming up in the January Newsletter: Part II: video preservation and what a producer can do to prepare for the future.


For more information about the Academy of Motion Picture Arts and Science’s Science and Technology Council, please visit: