Digital preservation

Examples of the scanned image quality from degraded negatives. Images: © Estate of Denis George / ANMM Collection ANMS1274[615] and ANMS1273[043].

Examples of the scanned image quality from degraded negatives. Images: © Estate of Denis George / ANMM Collection ANMS1274[615] and ANMS1273[043].

It’s in the nature of all materials to degrade and break down, some faster than others. Even with our conservation, preservation and archiving techniques designed to slow that degradation, objects from our collection need a bit of extra help to survive. While digitising the National Maritime Archive last year, I came across a surprising discovery: a collection of photographic negatives that were degrading while in our archive storage.

Our Paper Object Store is climate controlled at a constant temperature of 23°C with relative humidity at 50%. And yet, even these ideal conditions had not stopped these objects from developing an odour and a damp appearance.

affected_negative_2

An example of degrading film with farrowing and discolouration. Image: Kate Pentecost / ANMM.

 

affected_negative_1

Curling of the negative strips. Image: Kate Pentecost / ANMM.

The negatives came from the Denis George Collection. Denis George was a post-World War II Greek migrant who devised a new technique to artificially seed pearls, resulting in establishing a pearl cultivation industry. He adapted dental instruments to seed pearl making molluscs. These instruments and the operations of his Papua New Guinea pearl farm were documented on the affected negatives.

ANMS1275[297]

Denis George developed artificial pearling techniques. Image: © Estate of Denis George/ ANMM Collection ANMS1275[297].

After some investigation with our Senior Paper conservator, Caroline Whitley, it was determined that the negatives were degrading in a process called Vinegar Syndrome. The process of vinegar syndrome is inherent to the cellulose acetate base of the film stock. Exposure of acetate negatives to heat, moisture and/or acids enables and speeds up this process.

Acetic acid is released from the film base acetate molecules, causing the vinegar like smell. As the process continues the negatives experience shrinkage, curling and brittleness. Channels called furrows, develop on the negative and crystalline deposits of the acid appear on the emulsion. Pink or blue colour casts bleed through on the coloured film stock as the gelatin layer releases its dyes.

Once the vinegar syndrome has begun it cannot be stopped or reversed. It can only be slowed and managed.

The first step is to create a digital record of the negative to preserve the information in the picture before more of it is lost through the progression of the vinegar syndrome. Creating a digital copy of the negative also means that the original doesn’t need to be handled as much, minimising the further damage to the negative.

This was done through scanning the negatives as high-resolution TIFF files. TIFF files capture a high level of picture detail and allow us to record additional descriptive information, called metadata, with the image. Some negatives were scanned using the film frames for the scanner. Curled and buckled negatives were scanned between two sheets of Perspex to gently flatten the object.

The scanned TIFF images are then adjusted in Photoshop for contrast, brightness and colour. Highly compressed JPEGS are produced for use in the collection management system and shared through our online collection.

The negatives are currently in the Conservation lab, undergoing cleaning and conservation. Shortly, they will be housed individually in non-acidic envelopes before being placed in cold storage for long term preservation.

— Kate Pentecost, Digital Curator. 

Want to see more of Denis George’s photographs exploring his efforts to modernise pearl culturing in Australia? Why not explore our online collection.

Notes

  • Images reproduced courtesy of the Estate of Denis George.
  • For more information on preserving photographic collections, check out the National Archives of Australia.

7 thoughts on “Digital preservation

  1. Hi KateI clicked on the “Read more….” link and I’ve attached a screen shot of what I got. I hope you think this is being helpful. I’m interested in preservation generally and as a Metallurgist I have an abiding interest in the preservation of marine metallic artefacts in particular, a field I’m hoping to become more proficient in. Best wishes

    Graham

    From: Australian National Maritime Museum To: emeri1@y7mail.com Sent: Monday, 14 November 2016, 16:04 Subject: [New post] Digital preservation #yiv2376518434 a:hover {color:red;}#yiv2376518434 a {text-decoration:none;color:#0088cc;}#yiv2376518434 a.yiv2376518434primaryactionlink:link, #yiv2376518434 a.yiv2376518434primaryactionlink:visited {background-color:#2585B2;color:#fff;}#yiv2376518434 a.yiv2376518434primaryactionlink:hover, #yiv2376518434 a.yiv2376518434primaryactionlink:active {background-color:#11729E;color:#fff;}#yiv2376518434 WordPress.com | Kate Pentecost posted: “It’s in the nature of all materials to degrade and break down, some faster than others. Even with our conservation, preservation and archiving techniques designed to slow that degradation, objects from our collection need a bit of extra help to survive. W” | |

    • Hi Graham, the link in the email must have played up. Fingers crossed it doesn’t happen again. Great to hear that the topic of preservation sparked your interest. – Kate.

  2. Hi Kate

    I’m really impressed with the work that you are doing. – well done!

    I am planning to digitise a number of black and white negatives which I inherited from my father. Many are from ww2, and while they aren’t showing any signs of vinegar syndrome, I’m guessing that its only a matter of time.

    I would be interested to know what type of scanning equipment you are using. My search for affordable commercially available scanning equipment has so far been unsuccessful – most seem to be designed to digitise 35mm strips, rather than old black and white 2inch by 2 inch, 2inch by 1inch etc stand alone negatives.

    Hope you can help. Incidentally the link above to the National Archives of Australia doesn’t appear to work,, I get a page not found error.

    Kind regards

    David Beard

    • Thank-you David.

      It is wise to start digitising your father’s negatives, as all film stock degrades with passing time. We use several scanners at the museum – Microtek and Canon scanners along with SilverFast scanning software and Adobe Photoshop to process the files.

      Our collection also has negatives such as you describe. Some scanners on the professional market will carry a range of frames to fit the various negative sizes; however, I’ve found you can still scan the negatives without the frames (as I have had to do with some collection items).

      There are three key features your scanner and software need when digitising negatives:
      1. A light in the lid your scanner to illuminate the negative as it’s scanned. For example, the light in this model: https://www.canon.com.au/scanners/cs9000f-mark-ii (Please note this is not an endorsement of the model, just illustrating a feature).
      2. Scan at a dpi/resolution of 300 or greater.
      3. Save your scans as TIFF files, then convert to JPEGs as needed. TIFF files retain more information and thus, create a more detailed digital copy.

      There’s some good introductory videos on Youtube and one last tip: always handle negatives with gloves as the oils on your fingers aren’t good for the film.

      Good luck! Thanks again for the comment and I’ve updated the link to the National Archives of Australia.

  3. Pingback: Showcasing the other 91% of the collection | Australian National Maritime Museum

Leave a Reply