Managing and Caring for Moving Image Collections

Transcription

1 Managing and Caring for Moving Image Collections The great majority of archives, libraries and museums in the London region which hold film and video collections will not have moving image archivists or conservators on their staff, and may not have access to specialist facilities or advice on all the practical issues that surround working with moving image materials. These notes give a starting point for the management and care of moving image collections. Basic advice is provided in three sections; Formats, Access and Preservation. To help you develop your moving image strategy beyond this, we have created a further page of links to sources of information and advice. This guidance is derived from information published by the British Film Institute and the National Film Preservation Foundation and has been compiled by London Metropolitan Archives. If, once you have read these pages, you need further specific guidance please contact: laurence.ward@cityoflondon.gov.uk

2 Film and Video Formats Most people s immediate concern when dealing with moving image material will be about the inherent dangers of nitrate film stock. The great majority of pre mm film has a cellulose nitrate base. Nitrate film is chemically unstable and highly inflammable. Once ignited it is hard to extinguish. Nitrate film should be treated as a hazardous material. If identified in your collection it should be kept as cool as possible, be stored in a vented container and kept separate from acetate reels. You should contact a specialist film archive for further advice. However, virtually all post mm film, almost all 16mm and almost all 8mm film used by amateur and independent film-makers is safety with an acetate or polyester base. Help is provided in this section to identify your film and video holdings. It s possible to encounter a wide variety of formats when working with film and video. Below we have provided an overview of the basic film base polymers (the material that film is made from) and common carrier formats. Check our Further Guidance page for links to sites which contain more information on formats and film. Film Base Polymers The films and videos which you encounter will be made from nitrate, acetate or polyester stock. Each has unique properties which must be carefully considered when making provision for storage and preservation. Nitrate When motion picture film was introduced in the 1890s, cellulose nitrate was the only available transparent plastic durable enough for movie cameras and projectors. While strong and flexible, nitrate base film has a singular downside: It is highly flammable. Nitrate fires are virtually impossible to extinguish once they start burning. Most 35mm film stock before the early 1950s had a cellulose nitrate base. Because of its flammability, nitrate base film stock was not used for 16mm and 8mm film and was not sold by Kodak to the home market. As a precaution, from the mid 1920s on, Kodak labelled many of its nitrate stocks with the words NITRATE FILM along the edge to distinguish it from the materials intended for hobbyists. Acetate Manufacturers found a safe substitute for cellulose nitrate by exploring plastics in the cellulose acetate family. Beginning in 1909, a number of new acetate bases were introduced starting with cellulose diacetate 7, then, in the 1930s, cellulose acetate propionate and cellulose acetate butyrate and finally, in the late 1940s, cellulose triacetate 8. Generally speaking, all relatively nonflammable substitutes for nitrate are called safety film. Kodak acetate film often has the words SAFETY FILM printed along the edge. Polyester In the mid 1950s, Kodak began selling a new type of safety film made of polyester. Polyester is the toughest and most chemically stable film base used today. Because it is so strong, polyester can be made thinner than other types of motion picture stock. In addition, its tensile strength makes it less vulnerable to physical damage caused by improper handling. However, there is a negative aspect to this strength as playback equipment can be damaged in the event of jam. Polyester is the film stock now generally used for new 35mm release prints shown in cinemas. Unlike nitrate or acetate film, polyester cannot be spliced with currently available film cement. It can, however, be spliced with splicing tape or an ultrasonic splicer. Under similar storage conditions, polyester far outlasts other types of film. Polyester is sold under various trade names, such as Cronar (Dupont) and ESTAR (Kodak)

3 There are many methods we can use to identify a film base. A few examples are given here for reference, but you should refer to the Film Handling and Inspection section of The Film Preservation Guide (see Further Sources of Guidance below) for greater depth. The words "nitrate" or "safety" is often printed on the edge of a film. Kodak did not manufacture nitrate film after 1951 and no polyester film before Red and green interference colours are visible in polyester film when viewed through crosspolarized filters. Nitrate film is soluble in a variety of solvents - namely methyl alcohol, ethyl, and ether. Light will shine through a backlit roll of polyester film, but not acetate. Carrier formats - Film 8mm Aka Standard 8: film that is 8mm wide, with small square perforations on the edge of the film. Most commonly used as a medium for home movies and other amateur film-making, from Super 8 Film that is 8mm wide, with smaller rectangular holes, enabling a larger picture area on the edge of the film. Most commonly used as a medium for home movies and other amateur film-making, from mm Film that is 9.5mm wide, with rectangular perforations in the middle of the film between frames. Most commonly used as a medium for home movies and other amateur film-making, and also commonly used for distributing printed down versions of commercially produced films for home use, from mm Film that is 16mm wide. Used for various professional (non-theatrical, including television) production, for distributing printed down versions of commercially produced films, and as a medium for home movies and other amateur film-making, from mm Film that is 35mm wide. Used for various professional, including all theatrical, production and distribution, from At the end of these notes you will find the film gauge identification sheet which has been created by the Scottish Screen Archive to help work out which formats you have in your collection. Carrier Formats - Video VHS/S-VHS Standard domestic recording and playback format from early 1980s. Super-VHS (S-VHS) is a significantly higher-quality version of this format in Never used in professional production, but commonly used for amateur production into 1990s. Hi-8 Higher quality amateur format, commonly used for more advanced or semi-professional amateur production from late 1980s. Cassette is very small, and the tape is fragile

4 DV Name for a family of currently popular and relatively high-quality digital formats (including DV-Cam, DVC-Pro and mini-dv) used both for less expensive professional production and amateur production since mid-1990s. U-Matic Format used for some broadcast and much non-broadcast professional and semi-professional production through 1980s and early 1990s, now largely obsolete. Actually two formats: Hi Band and Lo Band U-Matic. The latter in particular is of relatively low quality. Beta SP Betacam SP. Format used for most broadcast and non-broadcast professional production from High quality. Digibeta Digital Betacam. Today s industry standard, used for almost all broadcast and much non-broadcast professional production from Very high quality. Betamax Early competitor to VHS as domestic format. Became obsolete. Other Other formats common from 1970s through early 1990s were large 1 and 2 tapes however, these were largely confined to broadcast television and are now obsolete. There are also a large number of early (1960s/1970s) video formats, often on open reels also now obsolete. Multimedia formats include laserdiscs, CD-ROMs and DVDs, as well as digital files stored on hard drives or networks. Note Downloadable charts giving film footage: screening time ratios and standard running times for various video formats can be found on the website of the commercial film laboratory, Stanley Productions: Access Viewing Copies Original material should be handled as little as possible and as a general rule should never be projected. User access should always be to viewing (or surrogate) copies with the original being retained as a master unless you can be sure that a copy of the title with identical content and of equivalent or higher quality is being acceptably preserved elsewhere. The viewing copy might be in a different format from the original, including digital files as well as film or video tape. However, unless you have a lot of projection equipment in excellent working order, and staff with the relative skills to operate it, the chances are you will not wish to make the very considerable investment of producing viewing copies on film. In which case, you can chose to either buy in projection equipment and the skills to operate it correctly, or send your films to a film lab competent to deal with archive material for transfer to a format which you can use (generally VHS video or digital). Even if the goal is simply to create a reference-quality viewing copy such as a VHS, DVD or encoded file, it is strongly recommended that a video 'sub-master' should be created at the same time on a better quality format, such as Digibeta. This is particularly important where the material is likely to be unique to your collection as it will greatly reduce the likelihood of having to return to the original master when generating replacement copies. It will also ensure that broadcast quality - 4 -

5 material is available in the event of its being needed, for instance for reuse in a television production or DVD compilation. Before making access copies, you should always check to make sure that a VHS or digital copy does not already exist elsewhere. Buying in a copy or directing your user to another office may save a lot of time and money. If (and only if) it is possible to establish safe in-house film projection, one way to create a cheap, but low quality, access copy is to project the film onto a wall and capture the image using a video camera. You should only ever try this if the film is in good condition and you have suitable, well maintained projection equipment and a competent projectionist. For VHS video it is possible to make good viewing copies with a minimal amount of equipment, as direct copying is possible with two players. It is also possible to create digital copies from VHS with a PC, the right connection leads and software. At the other end of the quality spectrum, laboratory transfer can be an expensive process, particularly for older formats. One way to reduce the cost is to process bulk orders. If you only have a small amount of material to transfer it makes good sense to approach other archives to discuss a co-operative approach which may realise greater savings. You may wish you use London s Screen Archives e-discussion list to achieve this. In all cases, it is desirable to produce a digital viewing copy. The great advantage of digital files is that they can be accessed through a PC and are easy to distribute through the Internet or on DVD. However, be aware that even a short film is likely to create a very large digital file, even when converted to common format such as.wmv (Windows Media Video). Ultimately a Digital Mass Storage system may be the most economic solution for the long term management of a digital moving image collection

6 Film Viewing Equipment Don t throw away equipment which is outdated. While it may seem unlikely at the moment, high quality VHS video players will soon be difficult to find and expensive to buy. Obviously, it s always preferable to have high quality equipment rather than bargain basement players which may damage your tapes during playback. If you want to use older formats in-house, make sure that equipment is always operated by someone who understands how it works. It s a good idea to employ a technician who has experience with the equipment in question. Although technicians skilled in using older projection equipment are increasingly hard to find, one possible solution is to advertise in the trade press. You can use EBay to source playback equipment but never assume that something you buy from a private seller will be in perfect working order. Make sure that the equipment is fully serviced by a qualified technician before use. You should also make sure that all your equipment is regularly cleaned and serviced. Standard viewing equipment includes: Film Projectors Still available for all formats. Projection was by far the most common method of viewing material originally and is still used extensively for screening material to audiences today. However, standard projectors are not designed to handle archival material and projection can cause major damage to film. Projection should only be used when screening viewing copies to audiences, and never with original or master material. Film Viewing Machines For 35mm and 16mm. Viewing tables, also known as editing tables or by the makers name Steenbeck, are by far the safest method for individual researchers and staff to view film. Most specialist film archives will have Steenbecks. This equipment needs careful handling however, and, again, should only be used in exceptional circumstances for viewing master copies or original material. A variety of viewing machines for the smaller amateur formats were available for home use and, if available and well maintained, can be used with extreme care and for archival purposes. Again EBay can be a useful source for viewing tables. Video Viewing Equipment Recording and playback equipment is available for all current formats. Video projectors are also now quite widely available. In some cases (e.g. Digibeta) the cost is very high. Equipment still exists for most obsolete formats however, in many cases only a few machines are still extant and are usually to be found at specialist video and television archives. Often, they require specialist engineering skills to maintain. Digital Viewing Digital moving images which have been encoded can also be stored, opened and viewed, and can also be distributed, by internet. Encoded moving images can also be put onto DVD and other multimedia artefacts. Copyright Physical ownership of moving image artefacts does not in any way imply intellectual property ownership over their moving image contents. Physical owners of material, including heritage institutions, are therefore required to comply with copyright legislation as this applies to moving images (in addition to any contractual arrangements specific to collections donated or deposited with them). This may limit the access that institutions can legally provide to material, particularly in public venues, off-premises and for re-use by third parties

7 Preservation The first thing that you should do for your moving image collection is to store it in appropriate conditions. All further issues are irrelevant if the collection is not cared for correctly! Every minute that a film is stored at the wrong temperature causes further degradation, to the point where the playback is no longer possible and the information is lost. Film and video in general should be stored at low temperatures and low relative humidity (RH) levels. Stability is also a key consideration as small fluctuations in temperature and RH can be a major cause of deterioration. An ideal situation for storing film and video would provide at least three separately controlled secure environments to suit different film bases (for example one at 0-5 degrees centigrade 35% Relative Humidity, another at 5 8 degrees centigrade35% RH and a further area at degrees centigrade 40% RH). The table below provides an outline for storage conditions but it is recommended that you refer to The Film Preservation Guide (see Further Guidance below) for more information. Film Storage Recommendations Stock type Recommended temp range Recommended RH range Acetate*: Colour 0-5 degrees centigrade 35% Acetate*: B/W degrees centigrade 35% Nitrate* 5 8 degrees centigrade 35% Polyester degrees centigrade 40% Video / Magnetic degrees centigrade 35 40% DVD 4 12 degrees centigrade 35 45% *Nitrate and acetate base film should be frozen if there are signs of decay Source: British Film Institute and IPI Media Storage Quick Reference Once you have stored your film and video collection in appropriate conditions, the next step for most archivists is a survey to further identify the items in the collection. Refer to the The Film Preservation Guide (see Further Sources of Guidance below) for a full overview of how to handle a film and inspect it for information which will provide the basis of your catalogue entry. Even if you do not have the necessary playback equipment required to view a film, it is still possible to establish a good level of information from it with cotton gloves, a light box, a loupe and careful handling. The table on the next page lists different types of film damage and decay and suggests a variety of practical steps which you can take to improve the situation. In general, improving storage conditions is the best way to treat film decay

8 Film Damage and Decay Damage/Decay Detection Method Symptoms Solution Nitrate Decay Acetate Decay Decay of Magnetic Sound Track on Acetate Film Mechanical Damage (all film gauges) Visual Inspection Smell Rusty metal cans Visual Inspection A-D Strips* Smell Visual Inspection A-D Strips* Smell Visual Inspection Stages of Nitrate Film Decay 1. Image fading. Brownish discolouration of emulsion. 2. Sticky emulsion. Faint noxious odour. 3. Emulsion softens and blisters with gas bubbles. Stronger odour. 4. Film congeals in solid mass. Strong noxious odour. 5. Film disintegrates into brown powder Vinegar odour Shrinkage Loss of flexibility; curling Cracked emulsion White powder on edge Magnetic track sheds, sticks and separates Vinegar odour Film base loses flexibility Tears, torn or broken perforations, broken splices Colour Fading Visual Inspection Shift in colour Loss of contrast and colour balance Film looks washed out Careless Handling Visual Inspection Dirt Surface scratches Mold, Mildew and Visual Inspection Matte-white spots on Fungus exterior of film roll Growth into white web Slow decay by improving storage conditions Copy content before decay is too advanced Dispose of films in advanced stages of decay as hazardous waste Slow decay by improving storage conditions Isolate infected films Copy content before decay is too advanced Slow decay by improving storage conditions Copy sound as soon as possible Physical repair by specialist Slow decay by improving storage conditions Copy content before decay is too advanced Specialist cleaning and treatment Improve Storage Conditions Source: The Film Preservation Guide: The Basics for Archives, Libraries, and Museums. Produced by the National Film Preservation Foundation - 8 -

9 Nitrate Decay Most people s immediate concern when dealing with moving image material is usually about the inherent dangers of nitrate film stock. The great majority of pre mm film has a cellulose nitrate base. Nitrate film is chemically unstable and highly inflammable. Once ignited it is hard to extinguish. Nitrate film should be treated as a hazardous material. If identified in your collection it should be kept as cool as possible, be stored in a vented container and kept separate from acetate reels. You should contact a specialist film archive for further advice. A useful list is given on the website of the film archive forum: However, virtually all post mm film, almost all 16mm and almost all 8mm film used by amateur and independent film-makers is safety with an acetate or polyester base. There are crucial chemical differences between black & white and colour film. In black & white films the image is made of silver metal particles. Unless it was poorly processed at the outset, the silver image will remain stable unless exposed to high humidity or contaminants. Most colour processes are much less stable. Vinegar Syndrome One of the biggest problems faced by organisations responsible for small moving image collections is acetate film base degradation or vinegar syndrome as it is commonly known. This condition is caused by poor storage as humidity, and heat can destroy the plastic base of acetate film. During this process the acetate catalyzes into acetic acid vapors which have a similar odor to vinegar and cause shrinkage of the film, acidification of the base and eventually the emulsion. While this is a relatively slow process, it cannot be reversed once started. During the early stages the film can be salvaged by transfer but if no action is taken, the film will eventually become too brittle to be played. The acetic acid vapour released by films with vinegar syndrome can infect other acetate base materials stored nearby. It is therefore vital that once decaying films are isolated as soon as possible. Even if the tell tale smell of vinegar syndrome is present in a collection, it s not always easy to identify which films are decaying. One simple way to check for acetate decay is to use A-D strips, produced by the Image Permanence Institute (see Image Permanence Institute entry in Further Guidance below). Preservation Copies Due to the fragility of film and video it is also often necessary to make copies for preservation purposes. This may be to transfer from nitrate to safety film, to transfer from acetate safety film which is suffering from Vinegar Syndrome or to retrieve content from obsolete formats. In this case, the new copy should also be treated as a master, replacing or supplementing the original. Wherever possible, any new master replacing an original should be on an appropriate format. For example, a new master from a title originating on film should usually also be on film of an equivalent format, even though a viewing copy created at the same time may be video or digital. A new master taken from an obsolete format should be on to a current format of equivalent or greater quality

10 Further Sources of Guidance Further Reading Film Preservation Handbook tion+handbook?opendocument Videotape Preservation Handbook The Film Preservation Guide: The Basics for Archives, Libraries, and Museums Audiovisual Archives: A Practical Reader The Dangers of Cellulose Nitrate film Audiovisual Archives: A Practical Reader Presto Space Preservation Guide (A site which gives general guidance on audiovisual preservation and digitisation.) Archives, Professional Bodies and Associations Association of Moving Image Archivists (Website for AMIA: international, US-based, membership organisation for those with moving image archive interests). Film Archive Forum (Website for UK Film Archive Forum: major public sector UK moving image archives.) Film Forever (Website providing advice to those storing films outside specialised archives.) International Association of Sound and Audiovisual Archivists International Federation of Film Archives (Includes online copies of the Journal of Film Preservation.) The Moving Image Society (Includes order form for BKSTS series of wall charts illustrating all significant film and video formats.)

11 National Film Preservation Foundation (Basic preservation guidance provided by the National Film Preservation Foundation in the USA.) National Film and Sound Archive (National Film and Sound Archive of Australia.) Presto Space (A website for archive owners and the public alike, which provides first point-of-call for information on audiovisual storage. The site provides information and management tools on digital technology for the storage of film, video and audio content and associated metadata. The information covers the state-of-the-art in storage technology, and includes forecasts of trends over the next twenty years.) Society of Archivists Film & Sound Group (See also their publication, Best Practice Guideline on Film and Sound Archives in Non-specialist Repositories (2001), available direct from the Society.) Copyright British Film Institute (A summary of moving image legislation, including copyright legislation.) UK Copyright Service (For general advice about UK copyright, including moving image copyright.) Training TAPE (Training for Audiovisual Preservation in Europe) (TAPE was established under the Culture 2000 programme of the EU as a project for raising awareness and training through meetings, research, publications and workshops.) Equipment Conservation by Design (Sell films cans and other useful equipment.) Image Permanence Institute (Buy A-D strips here.) Formats The Lab Guys World (A useful site charting the history of video, before VHS and Betamax. Includes an extensive links page for film and video websites.)

12 Film and Video Transfer If you decide to transfer film and video to VHS or digital formats, make sure that the company you use has good experience of working with archival material and understands the need for careful handling and use. The companies listed below have archival experience (although they are in no way endorsed by London s Screen Archives). Cinelab London Cinesite East Anglian Film Archive (small gauges) Prestech Film Laboratories Limited Stanley Productions (Website includes charts giving footage /screening time ratios.)

13 FILM GAUGE IDENTIFICATION 35mm 35mm. Introduced c Made on nitrate stock until present, produced on safety stock. To identify nitrate you will have to look along the edge markings beside the perforations. Nitrate will either have the word nitrate written along the edge, or a small star/explosion symbol will be present. Safety stock will have the word safety written aling the edge of a S will be present. If there are no markings present and the images appear to date from between 1895 and 1952, presume the film is nitrate and the Archive will conduct tests to confirm whether the film is nitrate or safety stock. For more information please see: 16mm Silent Stock 16mm Silent Stock. B/W introduced Colour introduced Always produced on safety stock. 16mm Sound Stock 16mm Sound Stock. B/W introduced Colour introduced Always produced on safety stock. 9.5mm 9.5mm. Introduced Always produced on safety stock. std.8mm std.8mm. Introduced Always produced on safety stock. super.8mm super.8mm. Introduced Always produced on safety stock. EXAMPLES OF FILM GAUGES ARE TO SCALE: PLACE YOUR FILM BESIDE EXAMPLES TO FIND MATCH