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Film preservation

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The film preservation movement is an ongoing project among filmmakers, historians, archivists, museums, and non-profit organizations to rescue aging film stock and preserve recorded images.

The process

Literally thousands of silent films were made in the years leading to the introduction of sound, but a considerable number of those films (historians estimate between 80 and 90 percent) have been lost forever. Movies of the first half of the 20th century were filmed on an unstable, highly flammable nitrate film stock, which required careful preservation to keep it from decomposing over time. Most of these films were not preserved; over the years, their prints simply crumbled into dust. Many of them were recycled, and a sizable number were destroyed in studio fires. As a result, silent film preservation has been a high priority among movie historians.

Because of the fragility of film stock, proper preservation of film usually involves storing the original prints in climate-controlled storage facilities, preferably ones with decent air circulation and refrigeration. The vast majority of films are not stored in this manner, which has resulted in the widespread decay of film stocks.

The problem of film decay is not limited to silent films. Movie industry researchers and specialists have found that color films (especially ones made in less expensive, less permanent processes than Technicolor) are also decaying at a rapid pace. A number of well-known films only exist as copies of their original master prints, because the originals have become unusable.

"Preservation" of film usually refers to physical storage of the film in a climate-controlled vault, and sometimes to repairing and copying the actual film element. Preservation is different from "Restoration." 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.

In most cases, when a film is chosen for preservation and/or restoration work, new prints are struck from the original negative or composite restoration negative for general viewing and preservation elements, such as fine grain master positives and duplicate printing negatives, are generated to make duplication masters available to future generations.

Sometimes (when budgets are lower) the images are transferred to video or digital media for easy transport and copying. Film preservationists would prefer that film images be eventually transferred to other film stock, because no digital media exists that has proven truly archival, while a well fixed and stored, modern film print can last upwards of 500 years.

While some in the archvial 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 is increasing to the point where the human eye has difficulty perceiving the difference between filmed images and digitally transferred images.

The movement

The cause for film preservation came to the forefront in the 1980s and early 1990s when such famous and influential film directors as Steven Spielberg and Martin Scorsese contributed to the cause. Spielberg became interested in film preservation when he went to view the original master print of his film Jaws, only to find that it had badly decomposed and deteriorated -- a mere fifteen years after it had been filmed. Scorsese drew attention to the film industry's use of color-fading filmstock through his use of black and white film stock in his 1980 film Raging Bull.

The film preservation movement has resulted in a number of classic films being restored to pristine condition. In many cases original footage that had been excised (or censored) from the original print has been re-inserted into the films. For a few early films stored in the Library of Congress, the only copy of them was rolls of paper which have the photographed images that the lost filmstock contained. For these, a optical printer was used to copy these printings on to safety filmstock.

Another high profile restoration by staff at the British Film Institute's National Film and Television Archive is the Mitchell and Kenyon collection, which consists almost entirely of actuality films commissioned by travelling fairground operators for showing at local fairgrounds or other venues across the UK in the early part of the twentieth century. The collection was stored for many decades in two large barrels following the winding-up of the firm, and was discovered in Blackburn in the early 1990s. The restored films now offer an unparalleled social record of early 20th Century British life.

In the age of digital television, HDTV and DVD, film preservation and restoration has taken on commercial as well as historical importance, since audiences demand the highest possible picture quality from digital formats.

A number of "lost" movies have become legends in themselves. These movies were either extraordinarily successful or controversial, but all prints of the original films have been lost because they decayed or were destroyed, and thus they were unable to be preserved. Examples of such "lost" films include Greed, London After Midnight, and even the original master print of Citizen Kane.

Film Restoration Issues

Main problems in restoring film

  • Dirt, dust
  • Scratches, tears
  • Color fade, color change
  • Film grain noise - a copy of an existing film has all of the film grain noise from the original as well as the film grain noise in the copy
  • Missing scenes and sound; censored or edited out for re-release.
  • Shrinkage: linear and "across the web" (width), as well as localized puckering around large 1 to 2 peforation film cement splices, most common in silent and very early sound films. Highly shrunken film, 1.5% or higher, must be copied on modified equipment or the film will likely be damaged.

Modern, digital film restoration follows the following steps

  1. Expertly clean the film of dirt and dust
  2. Repair all film tears with clear polyester tape or splicing cement
  3. Scan each frame into a digital file
  4. Restore the film frame by frame by comparing each frame to adjacent frames. This can be done somewhat by computer algorithms with human checking of the result.
    1. Fix frame alignment - Fix jitter and weave - the misalignment of adjacent film frames due to movement of film within the sprockets. This corrects the issue where the holes on each side of a frame are distored over time. This causes frames to slightly be off center.
    2. Fix color and lightning changes - This corrects flickering and slight color changes from one frame to another due to aging of the film.
    3. Restore areas blocked by dirt and dust by using parts of images in other frames
    4. Restore scratches by using parts of images in other frames
    5. Enhance frames by reducing film grain noise. Film foreground/background detail about the same size as the film grain or smaller is blurred or lost in making the film. Comparing a frame with adjacent frames allows detail information to be reconstructed since a given small detail may be split between more film grains from one frame to another.

Modern, photochemical restoration follows roughtly the same path:

  1. Extensive research is done to determine what version of the film can be restored from the existing material. Often, great pains are take to search out alternate material in film archives around the World.
  2. A comprehensive restoration plan is mapped that allows preservationists to designate elements as "key" elements upon which to base the polarity map for the ensuing photochemical work. Since many alternative elements are actually salvaged from release prints and duplication masters (foreign and domestic), care must be take to plot the course at which negative, master positive and release print elements arrive back at a common polarity (i.e., negative or positive) for assembly and subsequent printing.
  3. Test prints are struck from existing elements to evaluate contrast, resolution , color (if color) and sound quality (if audio element exist).
  4. Elements are duplicated using the shortest possible duplication path to minimize analog duplication artifacts, such as the build-up of contrast, grain and loss of resolution.
  5. All sources are assembled into a single master restoration element; most often a duplicate negative.
  6. From this master restoration element, duplication masters, such as composite fine grain masters, are generated to be used to generate additional printing negatives from which actual release prints can be struck for festival screenings and DVD mastering.


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