Just as your grandparents’ photo albums may have survived decades of neglect up in the attic, 8mm and 16mm films have proven remarkably durable over time, with many original films from the 1920s still viable for transfer and viewing today. When record albums began appearing on compact discs (CDs) in the 1980s, many consumers thought the days of scratched LPs were over and that CDs would “last forever” – but scratched CDs turn out to be more annoying than scratched LPs, and any Netflix subscriber knows that DVDs freeze just as often as VHS tapes jammed – and none of these formats are as easy to repair and continue using as a broken 16mm film.
Professional film studios and archives continue to believe that re-printing films, frame-by-frame, onto fresh polyester film stock, while costly, remains the most secure strategy for long-term preservation. If you have material of exceptional significance and the funds to devote to their care, you should seek out a reputable lab that offers photochemical “film-to-film” processes. A transfer to Beta-SP tape format is a popular alternative, though the longevity of that medium is more suspect.
Digital approaches have the virtue of ease of reproduction: once the film is transferred, the resulting file can be duplicated any number of times, without loss of image quality. Again, though, media formats change so quickly in the digital age that one must be vigilant to “migrate” the digital files to each successive format or risk losing material to obsolescence. Storage on a digital hard drive may seem a promising approach, but no one knows how easy it might be to plug that drive into a device in the year 2075 and access its contents: the material upon which the data is stored could degrade, the hardware to access it could be hard to come by, and the software to decode the outdated digital file formats may be long gone. In contrast, a film element held up to the light of the sun will still display an image – and should be suitable for scanning with whatever technology emerges in the future.
For preservation purposes, it is vital to capture an uncompressed digital transfer of your movies. No digital format will have more information on it than the original film, but some digital files will contain more information, or more precise information, than others. For example, DVDs typically “compress” the data contained in the original film —rendering the file in a kind of digital shorthand– in order to fit the content on a single disk. Other applications, such as YouTube or web sites that stream video online, use different kinds of file formats and different kinds of compression. Converting a compressed video file from a DVD to a different compressed format for uploading to a web site can make viewing easier, but subsequent converted versions (or “derivatives”) on this chain will progressively worsen in quality. Think of what it looks like when you make a photocopy of a photocopy, and then copy the copy again—the same thing happens when you make multiple generations of derivatives for digital files. These derivatives are also inadequate for subsequent migrations to other formats. So for preservation purposes you will need a high-quality master of uncompressed digital files in order to make to make the best possible copies in whatever new formats emerge in the future.
For preservation purposes, you should also seek to include all available materials, not just the edited-down versions you may have produced for Access purposes. (Of course, preserving these multiple versions individually may also be desirable).