Tales from the film crypt

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A nitrate film vault in San Fernando Valley, California. Photo by Michael Cahill.

Film has its passionate defenders and its ardent critics. So, too, does digital. The rivalry has been building for over twenty years and the two haven’t always been perceived as playing well together. When you’re in the media preservation business and the casualties keep piling up, people keep asking the same question:

Which format holds up over time?

Early motion picture film: baptism by fire

In August 1889, Eastman Kodak began distributing photographic negatives on transparent nitrocellulose film—the first flexible, plasticized base that suddenly made movie film a viable medium. Nitrate, as it’s commonly known, was combustible; almost right away, chemists began working to develop a non-flammable replacement. But movies shot and distributed on nitrate would still dominate the entertainment marketplace for the next several decades.

Even as early as 1909, non-flammable, acetate-based film stocks had already made an appearance as “safety” film. Nitrate continued as the preferred media until the mid-1940’s, because its visual results were stunning. But nitrate’s volatility made theater owners nervous. With decomposition brought on by poor storage, the off-gassing of nitric acid fumes accelerated the danger of combustion. The last nitrate was produced around 1951-52, whereupon acetate took over as the preferred medium.

In this demonstration, a roll of nitrate set on fire continues to burn underwater. Photo by Michael Cahill.

Film preservation differences: nitrate, acetate and polyester

Where nitrate’s failing was combustibility, acetate soon revealed its own Achilles heel. Though not dangerous, when stored in a poor environment at high heat and humidity or exposed to acidic vapors from nearby degrading film, acetate stock undergoes a chemical reaction within the plastic base to form acetic acid. This reaction causes the material to become brittle and shrink. In turn, the acid spreads into the gelatin emulsion or into the air, creating a pungent odor.

This gradual form of chemical deterioration is known as “Vinegar Syndrome” and it’s the worst kind of cancer for acetate film. Molecular sieves added to film containers have been reasonably effective in diminishing the symptoms, and freezing film will suspend or even halt the advancement while frozen. However, no known method will reverse Vinegar Syndrome. When acetate film starts to emit that vinegar smell, its longevity takes a nosedive.

Deteriorated film. Photo by Michael Cahill.

Other common threats to analogue media assets:

  • Acids from non-archival storage wrappers and film containers
  • Oils from human fingerprints
  • Excess temperature and humidity

One format has surpassed all previous film media in this regard. Created in 1955 but not pressed into regular use until the 1990’s, polyester-based film stocks have proven far more resilient than acetate.

Kodak’s brand name for its version of this stock is Estar and it’s been employed for post-production, archiving and theatrical release prints because of its durability and resistance to deterioration and breakage. If a motion picture camera jammed during a take, Estar stock would not break but rather tear up the camera’s gears. For this reason, traditional acetate film stock is still used for filming instead of its polyester counterpart.

Yet as an archiving medium, Estar is unrivaled. If stored properly, Estar boasts a shelf life of better than 500 years. In fact, several major studios whose more successful features originate on digital have smartly elected to do “film outs” or digital printing one frame at a time onto Estar film stock for long-term storage. Even today nothing else has proven to outlast polyester film.

Digital cameras: the radical game changer

In 1973, a 22-year-old electrical engineer from Brooklyn named Steve Sasson went to work for Kodak. He was left to find a use for the newly-developed charge-coupled device (CCD) technology. CCD allows an electrical charge to be moved to an area where the charge can be manipulated, like conversion into a digital value.

In 1975, Sasson presented a new invention to Kodak’s senior staff. Management was unimpressed and, according to a New York Times article, they told him, “It’s cute. But don’t tell anyone about it.” 

Kodak dominated the film market worldwide at the time and saw little use for Steve Sasson’s digital camera. And the company felt digital would never rival print photography. Kodak made billions of dollars licensing its patent to other camera companies but didn’t even try to embrace digital camera technology until it was too late to catch up with the market.

At first the international filmmaking community was a tough crowd to convince. But technology improved by leaps and bounds and today, digital is the predominant creation standard for television and movies. Digital capture, post-production and distribution are now industry standards. Digital still and motion picture cameras now own 99 percent of the world’s image creation market.

In 2010, President Obama awarded Steve Sasson the National Medal of Technology and Innovation Award. Two years later, in 2012, Kodak filed for bankruptcy.

The new movie preservation dilemma

Once upon a time there was a magical medium called nitrate. It was beautiful, entrancing and everyone loved it, even though it was incredibly unstable. Fast-forward 100 years. Now there’s a magical medium called digital. It’s beautiful, entrancing and everyone loves it, even though it, too, is incredibly unstable.

As with nitrate and acetate, digital is burdened with its own archival demons. The innumerable ones and zeros captured on spinning and solid-state drives (SSD’s) are even more unwieldy than any of their preservation predecessors.

Not only are the formats numerous and varied, they’re subject to another kind of archival cancer—digital deterioration. More than a few feature films and TV shows have suffered significant losses of crucial footage and edits owing to corrupted drives. According to The Digital Dilemma and The Digital Dilemma 2, written by media authorities and published by the Academy of Motion Picture Arts & Sciences (AMPAS), hard drives and tapes are poor containers for long-term storage of film and photo files.

These widely respected publications address serious concerns about the longevity of digital motion picture materials and other audio/visual assets. Hard drives cannot sit unused on a shelf for five years or more and then be guaranteed to start up again, let alone retain all their digital content intact. Current migration protocols for digital assets require a data migration of all digital files at least every five years to the next generation of storage device. In addition to physical storage requirements, massive volumes of new storage technology multiply the price tag every half-decade. It’s an untenable formula and a financial sinkhole.

Magnetic media has proven only marginally better.

While magnetic formats such as LTO tapes have gotten a firm foothold on the storage market, the kind of digital longevity that would reassure preservationists is still well out of reach. Newer storage mediums like DOTS technology from Group 47 make confident claims of digital storage in a durable analogue format.

None-the-less, digital media overall has yet to arrive at a comfortable place for long-term storage.

The era of film-digital inclusion

Much as we strive to maintain stability, the artifacts of our history, art and culture have had a tough time hanging around intact. But we’re closer every day to stabilizing digital formats and securing another couple of centuries for much of our visual media.

It’s worth considering at this point that, were it not for digital technology, we would not have been able to rescue, recapture and revitalize so many films that would otherwise be lost. Not to mention the phenomenal advances in restoration, special effects and dynamic sound that digital has spawned. And still, Estar polyester film remains the only proven champ of lasting durability.

New polyester (Estar) film stock being digitized by our 10K scanner. Photo by Michael Cahill.

The specious argument of film versus digital no longer carries weight. Each format has its frailties and its virtues. No one format is better or worse than the other overall. But combined they require a unified protocol of care and feeding to survive. Think of it this way:

Digital is expedient—Film is archival.

It has often been suggested that in a perfect world, the prudent producer would follow this process:

  1. Shoot in the format best-suited for a project.
  2. Cut, deliver and distribute the content digitally.
  3. Burn an Estar master and backups for preservation.

This appears to make the most economic and archival sense.

We live and work best in an industry of diversity and inclusion. We’re happy to leave outdated tropes in a crypt. For everything else, our vaults have plenty of room and ideal archival conditions.

Michael Cahill

Michael Cahill

Michael Cahill is a Photo Archivist at LAC Group.
Michael Cahill

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