(Part One of this article examined issues and problems in preparing and restoring classic motion picture footage for viewing on high-definition television. Part two examines additional problems encountered in repurposing older motion picture footage and some of the processes that can be used to overcome the effects of time on film.)
Reposing in storage facilities around the country are millions of feet of motion picture film that hasn’t seen the light of a projector or printer for decades.
Some of this footage is carefully tended—safe from temperature and humidity extremes, even from the effects of a nuclear blast. Other film isn’t so fortunate, having been relegated to a dusty unheated warehouse or a dank basement.
With the advent of HD and now the Blu-ray home entertainment business, some of this material could be a prime candidate for repurposing and a new revenue stream for its owners.
However, there can be surprises waiting when decades-old cans are opened, regardless of how careful their storage.
(click thumbnail)The nitrate-based 35mm film (left) has begun to seriously deteriorate. Restoration was able to check further deterioration and restore some, but not all, of the original image.A POTENTIAL TIME BOMB
Problems with some older footage are not isolated to scratches and color image shifts; sometimes motion picture film can self-destruct. Some of it, in addition to turning into a “goo” that precludes any attempts at salvaging images, can also be dangerous, as it is flammable to the point of burning with explosive violence, and can self-combust.
Virtually all professional motion pictures produced until the early 1950s (including Technicolor releases) were shot on cellulose nitrate-based stock. Over time, this material can become unstable and sometimes dangerous. Notwithstanding the special handling and storage requirement mandated due to the instability of the film, nitrate stock can present some special challenges to the film restorer of today.
“We sometimes see active decomposition in nitrate footage,” said Russ Suniewick, owner of Colorlab Corp. in Rockville, Md. “We have to excise the affected areas. Then that presents the challenge of creating frames where frames no longer exist.”
Suniewick says that even though nitrate film does have a bad reputation for withstanding the tests of time, he has encountered a lot of 100-year-old film in surprisingly good condition.
“Sometimes theatre owners didn’t send the prints back to distributors; they may have just ‘deep-sixed’ them underground in the theatre basement, sometimes a nearly perfect storage medium,” Suniewick said. “Some of the longer films from the 1900s through the 1920s are now turning up in such good shape that we can pull a good polyester preservation master and not have to resort to frame-by-frame preservation.”
TECHNICOLOR’S YIELD TO PROGRESS
In the early 1950s the motion picture industry began to adopt cellulose triacetate safety-based film and eliminated some of the problems associated with nitrate stock. Another switch involved moving away from the classic Technicolor process with simpler cameras and more cost-effective “monopack” or single-strip color negative film from Eastman and others.
However, as users were eventually to learn, this film, while good at color image capture, did not possess the image permanence achieved with the Technicolor process. Over time, certain films developed a pronounced color shift. And while some formulations proved better than others, the greatest equalizer was the care and treatment that the footage received in the processing lab. Eastman and other manufacturers took a great deal of care instructing laboratories in proper development techniques. But human nature and economics being what they are, some labs experimented to see what they could get away with, cutting corners in processing operations.
(click thumbnail)Optical printers are used to copy motion picture footage as part of the preservation/restoration process. This unit was made by Oxberry and employs ‘wet gate’ technology for concealing scratches and other small film surface defects.It was discovered much later that residual chemicals left from improper washing could combine with excess humidity and trigger the so-called “vinegar syndrome” in which the film softens and shrivels, releasing acetic acid and its vinegar-like odor.
Just as with some human diseases, “vinegar syndrome” is contagious and can readily spread to nearby “healthy” film in the same facility. If this problem goes undiscovered and unchecked for too long, the print is hopelessly damaged and nothing can be done to save it.
Human factors can also affect the success with which a correctly hued print can be obtained for restoration and repurposing. As insurance, studios routinely made color separations from the edited color negative film. These were printed onto long-keeping black-and-white stock, and could provide access to proper colors even if the original were to suffer from color shifts. However, even this did not eliminate all problems.
In at least one attempt to “remake” a correct color print from color separations, all did not go as planned. Decades earlier, the printer operator forgot to change filtration before the last pass was made, thus creating a yellow and two cyan separations. This went unnoticed for 40 years, only coming to light when it became necessary to recreate a full-color replacement of the badly faded major motion picture.
Film Technology Co. Inc. in Los Angeles is very much involved in restoration work, and its president, Ralph Sergeant, is aware of such preservation problems created by human factors.
“A lot of times the separation positives were made without anyone checking them,” Sergeant said. “Fortunately, digital processes can save your neck in most cases. If one color is lost, digital technology can approximate the correct color, depending on the scene content.”
In most restoration work, separation positives or “records” would not normally be used when restoring footage. They are viewed as a last-ditch fallback to be employed only when it’s absolutely impossible to take usable images from other film copies available. Also, separations do not always exist, as the policy at some studios was to produce them on a picture-by-picture basis only.
GETTING TO THE SOURCE
The most pristine source for repurposing or restoration work would be the original edited camera negative. However, due to its irreplaceable nature, this is not something that should be undertaken. Yet, some repurposing operations are doing just that.
“This is extremely dangerous,” said Paul Rutan, owner of Triage Motion Picture Services. “It’s very risky to work from a 50-year-old cut negative. They’re trying to bypass the restoration/preservation process for a capture in a highly transitory medium, and in doing so could possibly irreplaceably damage the original negative so that it cannot be retrieved in the future.”
He says a safer approach is to first obtain a high-quality photochemical protection master from a qualified film laboratory.
“The correct way to transfer older materials is to preserve the negative first by striking a fully color-timed and fully corrected liquid gate answer print,” Rutan said. “And then print a liquid gate interpositive to transfer from.”
Rutan’s company reproduces images on a frame-by-frame basis, restoring color where necessary, and recreating the brilliance and detail in black and white images. The resulting work is copied on modern polyestar-based film stock and is as close as possible to the original look.
In speaking with several motion picture restoration businesses, this is the favored approach—photochemically recreating the motion picture footage, and in the process, doing what is possible in terms of color correction, along with concealment of scratches and other defects. In many cases, the resulting film copy can then be transferred to digital by means of a high-definition scanner, such as the Thomson Spirit.
However, photochemical restoration can only go so far in readying older movies for HDTV screens. Impairments can still exist that would make an HD viewing experience less than satisfactory.
This will be addressed in the third and final part of this article.
James E. O’Neal has more than 50 years of experience in the broadcast arena, serving for nearly 37 years as a television broadcast engineer and, following his retirement from that field in 2005, moving into journalism as technology editor for TV Technology for almost the next decade. He continues to provide content for this publication, as well as sister publication Radio World, and others. He authored the chapter on HF shortwave radio for the 11th Edition of the NAB Engineering Handbook, and serves as editor-in-chief of the IEEE’s Broadcast Technology publication, and as associate editor of the SMPTE Motion Imaging Journal. He is a SMPTE Life Fellow, and a Life Member of the IEEE and the SBE.
Future US's leading brands bring the most important, up-to-date information right to your inbox
Thank you for signing up to TV Tech. You will receive a verification email shortly.
There was a problem. Please refresh the page and try again.