How we preserve films
Get information about the ways we preserve NFU films and some projects we've finished.
The majority of the over 40,000 reels of film held by Archives New Zealand is comprised of National Film Unit productions. Preservation to ensure long term access to our taonga is a vital part of our mandate. The NFU holdings represent a significant contribution to Aotearoa’s documentary and cultural heritage. This has been recognised by the inclusion of the Weekly Review and Pictorial Parade series on the UNESCO Memory of the World New Zealand Register.
The physical preservation of films is a little different to that of our paper archives due to the materials that make up a reel of film. Film is made of a plastic substrate – the earliest forms being Cellulose Nitrate, followed by Cellulose Acetate and latterly a much more stable polyester. The substrate is coated with a silver gelatin emulsion which holds the captured image. Nitrate and acetate film materials have an inherent instability which means they will deteriorate over time.
This degradation process can be significantly slowed by storing films in cool and dry storage. At Archives NZ we have cool and cold storage vaults – ranging in temperature from 2° to 12° - to house our film holdings.
Cool storage will not prolong the physical life of nitrate and acetate films forever. To ensure that future generations can enjoy this rich content we have two film preservation programmes. The first is physically copying the film on to a more stable polyester base in our Film Preservation Laboratory. Our second method is to digitally preserve the films. For this latter programme of work we have engaged with an external vendor to preserve a number of significant NFU titles.
The most challenging of these projects was to combine the three separate images of This Is New Zealand (1970) in to one combined frame. Produced for Expo ’70 in Osaka the production used an innovative 3-camera rig to capture the content.
In order to screen the finished film three interlocked projectors were required to run the 3 reels of film simultaneously. The technical challenge meant the film was unseen for decades. Attempts were made to produce a single composite image on film through optical methods but the results saw a significant loss in the quality of the image.
Advances in digital technology brought the film back to the screen. Archives’ former Senior Advisor of Audio Visual Records, Dave Smith, worked closely with two of the film’s key creators, Hugh McDonald and Kit Rollings on the project. The three original films were scanned, graded, restored and combined into a single image. Additionally the stereo soundtrack was remixed in to a Dolby 5.1 surround sound track from the original three track premixes.
The final digital master of This Is New Zealand is now stored in our digital preservation repository.
Our first foray into 4k scanning was with Country Lads (1941) – recognised as the Unit’s first official film. Through the scanning process each individual frame of the film was able to be delicately copied. At nearly 9 minutes in duration approximately 13,000 frames of film were digitised (film runs through a projector at 24 frames a second).
Most recently we have worked with our external vendor to produce 4k scans of Letter By Robot (1960) and Night Flight (1951). As we mark 80 years since the origin of the National Film Unit we hope you enjoy these two additions to our online content.