The archive preserves films on film base, if the final version of the film was produced and released on film base, because
- film base has a superior life expectancy than other carriers of audiovisual information
- the possibility of screening the films in the original format is thus also preserved.
The archive preserves digitally born films as digital files. Films distributed in tape formats are digitized and preserved as digital files. The Archive does not record digital files onto film base support, since:
- information will be lost
- the possibility of making preservation elements on film base will be very limited in the near future
- the making of viewing elements in original format would involve costly digitization processes.
Estimates made by the Image Permanence Institute in Rochester indicate that films on film stock preserved in optimal conditions have an expected life-span of >500 years, whereas the expected life-spans for harddrives (<10 years) and for magnetic tapes and discs (<50 years) is substantially shorter.
Films on film stock are best stored in a dry and cool climate in order to halt any chemical deterioration processes. The films in our collections are stored in optimally designed cold-storage vaults with a regulated temperature of between -6ºC and +6ºC, and in a relative humidity of between 25% and 35%. The climate in which we store our films is in accordance with recommendations from the Technical Commission of FIAF, the international federation of film archives. Read more in FIAF Technical Commission Preservation Best Practice.
In our collections we have DigiBeta cassettes and other tapes of films that were never produced or distributed on film. These tapes are stored in archive facilities with a temperature ranging between 15ºC and 18ºC, as are sound mixes and other magnetic elements in our collections.
Digital masters and digital viewing elements are stored as JPEG2000 and WAV files, no matter what the original production or delivery files were. The files are stored on data tapes of different brands in two geographically separated tape robot systems.
For a more detailed account on our preservation and conservation policies, see Policy of the Archival Film Collections of the Swedish Film Institute.
Our nitrate collection is preserved in specially designed coldstorage vaults in Grängesberg. Photo: Mark Standley.