Film preservation
Film preservation, or film restoration, describes a series of ongoing efforts among film historians, archivists, museums, cinematheques, and non-profit organizations to rescue decaying film stock and preserve the images they contain. In the widest sense, preservation assures that a movie will continue to exist in as close to its original form as possible.
For many years the term "preservation" was synonymous with "duplication" of film. The goal of a preservationist was to create a durable copy without any significant loss of quality. In more modern terms, film preservation includes the concepts of handling, duplication, storage, and access. The archivist seeks to protect the film and share its content with the public.
Film preservation is not to be confused with film revisionism, in which long-completed films are modified with the insertion of outtakes or new musical scores, the addition of sound effects, black-and-white film being colorized, older soundtracks converted to Dolby stereo, or minor edits and other cosmetic changes being made.
By the 1980s, it was becoming apparent that the collections of motion picture heritage were at risk of becoming lost. Not only was the preservation of nitrate film an ongoing problem, but it was then discovered that safety film, used as a replacement for the more volatile nitrate stock, was beginning to be affected by a unique form of decay known as "vinegar syndrome", and color film manufactured, in particular, by Eastman Kodak, was found to be at risk of fading. At that time, the best-known solution was to duplicate the original film onto a more secure medium.
A common estimate is that 90 percent of all American silent films made before 1920 and 50 percent of American sound films made before 1950 are lost films.
Although institutional practices of film preservation date back to the 1930s, the field received an official status only in 1980, when UNESCO recognized "moving images" as an integral part of the world's cultural heritage.
The problem of film decay
The great majority of films made in the silent era are now considered to be lost forever. Movies of the first half of the 20th century were filmed on an unstable, highly flammable cellulose nitrate film base, which required careful storage to slow its inevitable process of decomposition over time. Most films made on nitrate stock were not preserved; over the years, their negatives and prints crumbled into powder or dust. Many of them were recycled for their silver content, or destroyed in studio or vault fires. The largest cause, however, was intentional destruction. As film preservationist Robert A. Harris explains, "Most of the early films did not survive because of wholesale junking by the studios. There was no thought of ever saving these films. They simply needed vault space and the materials were expensive to house." Silent films had little or no commercial value after the advent of sound films in the 1930s, and as such, they were not kept. As a result, preserving the now-rare silent films has been proposed as a high priority amongst film historians.Because of the fragility of film stock, proper preservation of film usually involves storing the original negatives and prints in climate-controlled facilities. The vast majority of films were not stored in this manner, which resulted in the widespread decay of film stocks.
The problem of film decay is not limited to films made on cellulose nitrate. Film industry researchers and specialists have found that color films are also decaying at an increasingly rapid rate. A number of well-known films only exist as copies of original film productions or exhibition elements because the originals have decomposed beyond use. Cellulose acetate film, which was the initial replacement for nitrate, has been found to suffer from "vinegar syndrome". Polyester film base, which replaced acetate, also suffers from fading colors.
Storage at carefully controlled low temperatures and low humidity can inhibit both color fading and the onset of vinegar syndrome. However, once degradation begins to occur, the chemical reactions involved will promote further deterioration. "There is no indication that we will ever find a way to arrest decomposition once it has started. All we can do is inhibit it," says the director of the AMIA board, Leo Enticknap.
Film decay as an art form
In 1991, filmmaker and former deputy director of the Eye Filmmuseum in Amsterdam, Peter Delpeut, made the film Lyrical Nitrate, with decaying films from the Desmet Collection.In 2002, filmmaker Bill Morrison produced Decasia, a film solely based on fragments of old unrestored nitrate-based films in various states of decay and disrepair, providing a somewhat eerie aesthetic to the film. The film was created to accompany a symphony of the same name, composed by Michael Gordon and performed by his orchestra. The footage used was from old newsreel and archive film and was obtained by Morrison from several sources, such as the George Eastman House, the archives of the Museum of Modern Art, and the Fox Movietone News film archives at the University of South Carolina.
Preservation through careful storage
The preservation of film usually refers to physical storage of the film in a climate-controlled vault, and sometimes to the actual repair and copying of the film element. Preservation is different from restoration, as restoration is the act of returning the film to a version most faithful to its initial release to the public and often involves combining various fragments of film elements.Film is best preserved by proper protection from external forces while in storage along with being under controlled temperatures. For most film materials, the Image Permanence Institute finds that storing film media in frozen temperatures, with relative humidity between 30% and 50%, greatly extends its useful life. These measures inhibit deterioration better than any other methods and are a cheaper solution than replicating deteriorating films.
Preparing a film for preservation and restoration
In most cases, when a film is chosen for preservation or restoration work, new prints are created from the original camera negative or from a composite restoration negative, which can be made from a combination of elements for general screening. It is therefore particularly important to keep camera negatives or digital masters under safe storage conditions.The original camera negative is the remaining, edited, film negative that passed through the camera on the set. This original camera negative may, or may not, remain in original release form, depending upon number of subsequent re-releases after the initial release for theatrical exhibition.
Restorers sometimes create a composite negative by recombining duplicated sections of the best remaining material, sometimes on "a shot-to-shot, frame-by-frame basis" to approximate the original configuration of the original camera negative at some time in the film's release cycle.
In traditional photochemical restorations, image polarity considerations must be observed when recombining surviving materials and the final, lowest generation restoration master may be either a duplicate negative or a fine grain master positive.
Preservation elements, such as fine-grain master positives and duplicate printing negatives, are generated from this restoration master element to make both duplication masters and access projection prints available for future generations.
Choosing an archival medium
Film as an archival medium
Film preservationists would prefer that the film images, whether restored through photochemical or digital processes, be eventually transferred to other film stock, because no digital media exists that has proven truly archival because of rapidly evolving and shifting data formats, while a well-developed and stored, modern film print can last upwards of 100 years.While some in the archival community feel that conversion from film to a digital image results in a loss of quality that can make it more difficult to create a high-quality print based upon the digital image, digital imaging technology has become increasingly advanced to the point where 8K scanners can capture the full resolution of images filmed at as high as 65 mm.
70 mm IMAX film has a theoretical resolution of 18K, the highest possible resolution given the sensor.
Of course, having an intermediate digital stage, followed by forming a new film master by lasering the digital results onto new film stock does represent an extra generation. So would an intermediate film master that was restored frame-by-frame by hand. The choice of film vs. digital restoration will be driven by the amount, if any, of restoration required, the taste and skill set of the restorer, and the economics of film restoration vs. digital restoration.
Digital as an archival medium
, digital scanners can capture images as large as 65 mm in full resolution. That is the typical image size on a traditional 70 mm film which used a portion of the film surface for its multitrack magnetic sound stripe. The cost of a 70 mm print of a two and a half hour film as of 2012 ran upwards of $170,000; while a hard disk capable of storing such a movie typically cost a few hundred dollars, with an archival optical disk even less. The problem of having to transfer the data as new generations of equipment come along will continue, however, until true archival standards are put in place.Digital film preservation
In the context of film preservation, the term "digital preservation" highlights the use of digital technology for the transfer of films from 8 mm to 70 mm in size to digital carriers, as well as all practices for ensuring the longevity and access to digitized or digitally born film materials. On purely technical and practical terms, digital film preservation stands for a domain specific subset of digital curation practices.The aesthetic and ethical implications of the use of digital technology for film preservation are major subjects of debate. For instance, the senior curator of George Eastman House Paolo Cherchi Usai has decried the shift from analogue to digital preservation of film as ethically unacceptable, arguing, on philosophical terms, that the medium of film is an essential ontological precondition for the existence of cinema. In 2009, the senior curator of EYE Film Institute Netherlands Giovanna Fossati has discussed the use of digital technologies for the restoration and preservation of film in a more optimistic way as a form of remediation of the cinematic medium, and has positively reflected on digital technologies' ability to broaden restoration possibilities, improve quality, and reduce costs. According to the cinema scholar Leo Enticknap, the views held by Usai and Fossati could be seen as representative of the two poles of the digital debate in film preservation. It should be kept in mind, however, that both Usai and Fossati's arguments are highly complex and nuanced, and likewise, the debate about the utility of digital technologies in film preservation is complex and continually evolving.