Cultural collections are often made from materials that are chemically unstable and slowing the deterioration of these items is the ongoing challenge of those who care for them. One of these materials is cellulose nitrate, a material that was used for motion picture films and still photography until the 1950’s. As the cellulose nitrate degrades it buckles and the image becomes distorted. It is not possible to stop this from happening, but it can be slowed by storing the cellulose nitrate material at cool temperatures in a special vault.
The National Library has a significant collection of panoramic negatives which are stored in this vault to slow their deterioration. The Enemark collection consists of over 500 negatives that were taken of country towns in New South Wales and Canberra in the early 1900’s by John H. Enemark. The negatives are very long, some up to 4 metres, and have been stored rolled up tightly inside cardboard boxes.
In order to improve access to these negatives, and provide a preservation strategy for their safekeeping, the National Library commenced a project to digitise every negative.
The project has involved some careful planning, and the creation of some new equipment in the photography department at the Library.
Because the negatives have been rolled for many years they have a strong curl, making it difficult to handle them. The first step involves unrolling the negatives and laying them flat for two weeks under heavy weights.
After this time the negatives are more manageable and our Pictures collection staff are able to accession them so we can individually catalogue the negatives.
Transporting the negatives around the building between Preservation Services and Photography became difficult once the negatives were flat. A tray, made from acid free corrugated board, was made so that the negatives could be securely held flat and then carried upright so that they would fit inside the lift.
Photographing negatives that are so long is not an easy task. The Library’s digitisation standards indicate that negatives are captured at 2000 dpi 1:1, however because of the size of these negatives we are using 1000 dpi 1:1. The negatives are photographed in sections and these are then digitally stitched together.
In order to undertake this work the Library developed a new piece of equipment that has been dubbed the ‘panorail’. This equipment consists of a table with a sliding glass sandwich surface. The negative is placed between the glass sheets and moved beneath a fixed camera. Marks on the glass indicate where the sliding glass sandwich needs to be placed in order for each slice to be captured. There is some overlap in each image so that the stitching process is seamless. These images are between 100 MB and 350 MB in size (16 bit grey scale).
The Library aims to have the negatives all digitised by the end of July 2013. These images will be available through the Library’s catalogue. The project has been supported with funding raised by the Library, and we thank these donors for their assistance for without it we would not have been able to preserve these important negatives.