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: .
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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-1951 35mm 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 1951 35mm 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 non-flammable 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).
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 1955.
§ Red and green interference colours are visible in polyester film when viewed through cross-polarized 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 1932.
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 1965.
9.5mm
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 1922.
16mm
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 1923.
35mm
Film that is 35mm wide. Used for various professional, including all theatrical, production and distribution, from 1895.
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 1986. 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.
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 1986. High quality.
Digibeta
Digital Betacam. Today’s industry standard, used for almost all broadcast and much non-broadcast professional production from 1994. 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: www.stanleysonline.co.uk.
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 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.
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 multi-media artefacts.