Film '93: a visit to BFI/NFTVA J Paul Getty Jr conservation centre, Berkhamsted

In March Alan Cummings, Helen Jones (RCA/V&A Conservation Course) and Megan Gent (MA student, Photographic Materials) visited the Conservation Centre to see their work and to take soundings about possible joint research/ training ventures for the future. The facilities were impressive and all the staff we met most helpful and accommodating. In half a day we could only see part of their work, missing out the processing side completely, but we gained an interesting insight into their preservation function and these are the impressions of a complete novice in this field.

The J Paul Getty Jr Conservation Centre was built for the British Film Institute about six years ago to house the National Film and Television Archive, though the archive has been in existence for more than sixty years and also operates other sites. The main function of the Berkhamsted site is the storage of the film stock (except nitrate film) and all the processes necessary for its preservation and use.

Preventive conservation through environmental control in the stores is crucial for the movie film. Great racks of acetate and video film are maintained at 35%RH and 18°C. Like most stores, these are filling up more quickly than had been anticipated, partly because the Archive is acquiring the stock from TV companies which recently lost their franchises. Though the main store for nitrate film is off-site - on a disused air-field - that being worked on passes through a special store where the aim is to control any explosion risk by isolating the film in several small, blast-proof cells. Though the building is designed to maintain low temperature and RH, the environment here is not controlled because it provides only temporary storage.

Work on the movie film is divided into discrete functions, with one department responsible solely for assessing the films as they come in. This involves winding the film, usually by hand, over a light box and examining it frame by frame with a magnifying glass. Details such as date, provenance, context and the condition are recorded on forms. Most common films can be dated by their codes, Kodak and Eastman having 'hallmarks' for each year, but a certain amount of detective work may be necessary to determine the date and even which side the film should be viewed from. We were shown some dramatic examples of deteriorated film, both nitrate and acetate disintegrating entirely after passing through a sticky, oozing phase and each giving off their characteristic acid smell.

An important role of this department is to detect any nitrate film. This could be found spliced into a reel with other types. If there is any doubt as to the nature of the film, a small sample of it is dropped into a jar of 1,1,1-trichloroethylene; acetate floats and nitrate sinks.

The physical repair of the films is a painstaking business. The word 'repair' is the most apt because no attempt is made to restore the image itself; the aim is to preserve and maintain the Archives collection. Tears and up to three missing sprocket holes are mended with film splicing tape - an adhesive tape with sprocket holes. Larger gaps are filled with replacement film. The dimensions of in-fill have to be matched to the old film, which may have shrunk in all directions, so a stock of old, blank film is kept for this purpose. Wide and untidy splices can interfere with the running of films through the projector so these are undone and re-made. No adhesive is applied to splices or other joins, the bond being effected by the action of solvents on the film itself. The staff make up their own 'nitrate cement' of two parts acetone to one part amyl acetate, while a commercially prepared film 'cement' works for both nitrate and acetate stock. New film is a polyester and cannot be joined by this method so it is heat-welded.

All of this work is done on what is essentially black and white film, though some of it may have been coloured after processing; we saw an example of a film hand-coloured by stencilling. If copies of colour film are required, the tints are recorded, a black and white copy made and the colour re-added during processing of the final version.

As well as the repair of the actual film, another kind of restoration activity takes place. This is the restoration of the content of the film. Separate editions of a film are examined and the best bits from each version amalgamated to make the best possible version from the extant material - an technique not normally open to conservators of museum objects! This approach may involve considerable research in deciding, for example, what a director originally intended, but no restoration in the sense of adding missing scenes or retouching images is done. While, of course, great effort is put into preserving the original film, the content appears to be paramount. and to some degree divorced from its physical medium. This may happen in other areas of documentary history, but film does not yet appear to have gained the status as objects that, say, books have.

Every film leaving Berkhamsted is finally checked for quality, both over a light box in the work room and by projection in one of the two small auditoria. Watching movies all day sounded like a great job to us but we were assured that much of the material is less than fascinating. However, the 1937 Movietone newsreel we were shown was a treat. Throughout these checks the soundtrack is examined as closely as the image.

The stills side of the Archive is, by admission of our host, Mike Caldwell, less sophisticated than that of movies. He works not only with stills from the movie films themselves, but also with publicity stills, posters and other related images. Interestingly, stills on nitrate film tend to be in better condition than those on acetate. This is because they were not usually stored in closed tins, as their movie counterparts were, so damaging vapours were more likely to be removed by air circulation.

Acetate films are actually a gelatine layer sandwiched between layers of acetate. On ageing the acetate loses its plasticizers, becomes yellow and embrittled, and can shrink dramatically. The gelatine, however, does not shrink appreciably The differential movement results in cockling and 'crazy-paving' blistering of the acetate layers. If the gelatine layer is substantial and complete, it is a relatively simple procedure to soak off the acetate, leaving a durable gelatine layer with the feel of flimsy carbon paper. However, with thinner, disrupted gelatine this is a much more tricky operation, though Megan had seen it demonstrated successfully.

Retouching of tie in the Olivier portrait using Adobe Photoshop (click image for larger version)

Mike Caldwell and Alan discovered a mutual enthusiasm for computer scanning and manipulation of images. Mike had worked with state-of-the-art equipment in a commercial firm and the print he showed us, taken by scanning an old print and producing a new negative was virtually indistinguishable from a good quality photographic print (totally indistinguishable to the unpractised eye!). The main advantage, though, was that a bad stain on the original print had been eliminated from the scan-print by 'retouching' it on the computer. The software used was similar to that used by some Conservation Course students at the Royal College of Art.

The technique was used at the RCA in the reconstruction of the Olivier portrait from the Theatre Museum collection. In this case a 35mm transparency of the original was scanned onto a Kodak PhotoCD at high resolution and then opened in Adobe PhotoShop on an Apple Macintosh Quadra computer. The image was retouched at a lower resolution and proofed on a Canon CLC500 colour photocopier. To reproduce the retouched image above, a digital halftone was made and directly imaged with the type on this page, which was then output through the RCA's Monotype Imagesetter for the V&A Press.

The scanning equipment is, of course, enormously expensive, but has great potential as a conservation tool. A problem is that, as with many tools and materials, it is not being specifically designed for conservation applications and it is up to the profession to recognise the potential of new technology and work with those developing it to ensure they are aware of our needs. The Course hopes to be active in this field and has initiated an M Phil. option based around 'Computers in Conservation' and the first student to take this up should start in October 1993.