Time-based media conservation technicians checking the alignment of an LCD projector
Time-based media conservation technicians checking the alignment of an LCD projector

Time-based media art

‘Time-based media’ refers to works of art which depend on technology and have duration as a dimension.

Tate’s collection of time-based media art spans the early 1970s to the present day. It includes artworks that use video, film, audio, 35 mm slide and computer-based technologies and focuses mainly on artists’ installations rather than single-channel works. It is, however, a fast-growing collection with an increasingly broad global reach, reflecting the interests of new curators.

Artists make very specific decisions in their choice of media and the way in which their work is presented. Specific display equipment might be important because of a particular quality of sound or image it creates, or because the artist has made conceptual links between a particular item of equipment and the meaning of the work. Specific technology places a work at a particular point in history and may convey ideas about the spirit in which the work was made.

Angus Fairhurst, 'Gallery Connections' 1995
Angus Fairhurst
Gallery Connections 1995
© The estate of Angus Fairhurst

Tate conservators must conceive of even the most recent works as the ‘future’s past’. This means being mindful of what will be important to a work in the future and what historical links should be maintained. It is particularly important when dealing with time-based media works which only really exist in their installed state, and where the relationship between the identity of the work and the status of the elements used in a display can often be unclear. Conservators enter into a dialogue with artists, technicians and curators in order to understand what it is important to preserve.

Conservators identify and assess the risks to a work of art from agents of deterioration and change, aiming to minimise undesirable change. However, time-based media works defy stasis: often, the conservator must manage intelligently the inevitable changes which come with a fast-changing technological environment and the effects of different installation spaces and conditions. The stronger the link between the meaning of a work and a particular technology, the greater the degree of loss if that technology becomes obsolete.

Time-based media works demand that we shift our gaze beyond the material to embrace the less tangible aspects of an installation. Consideration must be given to the details of the light levels, the physical relationship between components of the work, or the way in which the visiting public enters the space where the work is displayed. These, together with the more tangible material aspects of the technology, form the focus of our conservation efforts.

Time-based media conservation

Time-based media works of art differ from other works in the collection because of their dependence on technology and the significance of the less tangible elements of these works.

Whereas the physical deterioration of materials is the primary factor to address with traditional objects, industry decisions to discontinue particular technologies (a projector or tape format, for example) also affect time-based media, and vigilance is required to ensure that encoded media can be played back.

As with other forms of installation, it is essential that correct installation details are documented and that this information is made accessible to future custodians of the work.

Time-based media installations form complex systems; if one part breaks down or can no longer be supported, this usually has ramifications for the whole. In a multi-channel work originally designed with synchronised laser discs, for example, if the laser disc players can no longer be kept working, the time-code reader, the synchroniser and the computer programme at the heart of the work will also have to be revised.

The time-based media conservator is required to be proactive and pre-emptive in order to ensure that the works are preserved into the future.


Tate’s time-based media conservators aim to ensure that we can continue to display the collection of time-based media art long into the future. Time-based media pieces only really exist in their installed state, and so depend on a second stage of creation – their installation in the gallery – for their realisation. This process has to be recreated each time the work is installed.

Installation brings in a host of decisions which can ultimately change even the most tightly specified work. For example, the artist Bill Viola has specified every detail of his work Five Angels for the Millennium 2001, from how visitors should enter the display space to the scale of the images, the overall dimensions and the audio levels. Despite this, the work will necessarily be different every time it is installed, due to the architectural constraints of the overall space in which it is shown.

This work is owned jointly by Tate, the Centre Pompidou in Paris and the Whitney Museum of American Art in New York, and in the past few years the effects of these different spaces on the experience of the work have been seen.

Installation view of Bill Viola Five Angels of the Millennium 2001
Installation view of Bill Viola Five Angels of the Millennium 2001


Another important influence on time-based media art is its dependence on the fast-changing technological environment. Managing this requires detailed knowledge of the works themselves and a clear understanding of where the acceptable parameters of change lie. For example, projected images will be changed by the type of projector used. In order to manage the mutability of time-based media works, conservators and curators carry out extensive research in order to understand what is important to preserve in maintaining the fidelity of the work.

As well as the full range of new media, Tate’s collection of time-based media art contains work made using older technologies such as film and slide-based installations. Even some of Tate’s most recent acquisitions use these media, with many younger artists choosing to continue to work with these older technologies.

A preservation strategy is designed for each new acquisition, based on how each work was made and what is important to its ongoing preservation and display. Part of this process is to create display copies in order to ensure the long term preservation of the master materials.

The work of time-based media conservators is divided between activities related to acquisition, display and the ongoing care of the collection. Once a time-based media piece goes on display, it needs constant maintenance to ensure it remains running and stays looking its very best. This challenge is met collectively by the work of a specialist art handling team, vigilant gallery assistants and the conservation team.


For works made on video conservators create a preservation master on a non-compressed component video format. This provides a clear path for future migration of material and a stable professional format with reliable playback. These masters are then migrated every five years onto new stock and, in all likelihood, onto new formats. The goal is to minimise changes to the look and feel of the original. This requires not only an understanding of the technology but also an awareness of cutting-edge technological trends.

In recent years there has been a shift in artistic practice with regards to the making of video works. Advances in new technology mean that artists can now edit their work on a personal computer. Tate is already using computer servers to store some of these works and research is underway to move our audio, video and computer-based works into data storage.


Working with artists’ film requires a keen eye and commitment. Time-based media conservation relies on the few remaining 16 mm film laboratories to produce both archival and display material that strives to retain the quality of the original. When a film installation goes on display the prints are changed approximately every three weeks, due to the deterioration of the film as it runs through the projector. A display which lasts for a year will require up to a dozen prints.

In many cases the original negative of a film work will stay with the artist. For each newly acquired film work Tate produces an inter-positive from the artist’s negative, two inter-negatives and two check prints. The check prints confirm that the inter-positive and inter-negatives are as desired and make it possible to ascertain that the colour and contrast are correct. When Tate acquires a film work, the artist is asked for a copy of a print which can act as a reference. Tate is currently working to put all of its inter-positive, inter-negative material and reference material into cold storage.

Tacita Dean, 'Disappearance at Sea' 1996
Tacita Dean
Disappearance at Sea 1996
16mm colour film with sound
Purchased 1998© Tacita Dean, courtesy Frith Street Gallery, London and Marian Goodman Gallery, New York/Paris
Production diagram: the packing system for film works at Tate


Tate is currently working to put all of its inter-positive, inter-negative material and reference material into cold storage
Tate is currently working to put all of its inter-positive, inter-negative material and reference material into cold storage


Slide-based works

The common presentation technology of the day, 35 mm slides became a popular medium for artists in the 1970s. Despite the replacement of slide presentations by digital projection and software such as PowerPoint, artists continue to make installations using 35 mm film slides. This is, at least in part, due to the beautiful image quality which the medium offers.

35 mm slides present one of the greatest time-based media conservation challenges. Slides are taken as positives in the camera – there is no negative. From these original positives duplicates are made for display. Ideally, all original slides would be put into deep cold storage and never exposed to the risk of being used in the duplication process.

Currently, Tate’s conservators are exploring whether digital technology can capture the colour and resolution of a 35 mm slide accurately enough to act as a digital intermediate. Tests are being carried out to establish whether a digital intermediate will produce display copies of a quality which will satisfy the artists who work in this medium. The ultimate aim is to use digital files to create analogue 35 mm exhibition copies for display. Kodak stopped making its slide projectors in 2004. The SAV 2050 model, which is the one most commonly used by artists, stopped production considerably earlier, in 1984. Luckily there exists a group of dedicated enthusiasts who service and repair these machines, enabling Tate to continue to display these works using the original technology.

Colour display transparency light boxes

Karl Bush and Kate Jennings from Tate’s Conservation department consulting with Tony Maxwell from the National Physics Laboratory
Karl Bush and Kate Jennings from Tate's Conservation department consulting with Tony Maxwell from the National Physics Laboratory

Tate conservators also care for the colour display transparencies mounted in light boxes.

Tate owns a number of large colour display transparencies by the artist Jeff Wall and has been working with the National Physical Laboratory on using finite element analysis to investigate the physical stresses inherent in the design of these large structures. The aim of this study was to understand how best to safely display and transport these works.


Arup acoustic consultancy recording the hum of the Turbine Hall at Tate Modern
Arup acoustic consultancy recording the hum of the Turbine Hall at Tate Modern

Audio which has been produced via analogue technology is archived by digitising to 96 kHz and 24 bits per second (much higher than CD quality). Sound works in the collection include Tacita Dean’s installation Foley Artist 1996, an eight-channel audio installation; and Deiter Roth’s Harmonica Curse 1981, which involves 76 hours of recordings of the artist learning to play an accordion.

Computer technologies

In 2005 Tate made its first major foray into computer-based art when it acquired a work called Becoming2003 from the artist Michael Craig-Martin. Working closely with the programmer Daniel Jackson and AVCO – with the blessing of the artist – conservators were able to deconstruct this work. Programmer Daniel Jackson provided the gallery with the code he had written, and collaborated with conservators to identify how the code worked in relation to the assets, the 15 digital images and the parameters of the work, time, and degrees of transparency in the resulting image. This information forms the cornerstone to future strategies to ensure that the work remains displayable when its original technology becomes obsolete.

Performance and intangible works of art

In 2004 Tate acquired its first performance work, Roman Ondak’s Good Feelings in Good Times 2003, signalling the development of a new area of the collection. Our conservators worked closely with the curator of performance and the artists to develop appropriate conservation strategies for such highly intangible works.

In the case of Tino Sehgal’s installation This is propaganda 2002 the artist does not allow any documentation of the work, which attempts the complete disavowal of material remains. He rejects the use of certificates and instructions, photographs or videos, avoiding the possibility that these might, in time, come to stand-in for the work.

It is part of Tino Sehgal’s practice that when one of his works is bought, he not only conducts the transfer of title as an oral contract but he also teaches the new owners how to install the work. He calls his teaching method ’body to body transmission’, referencing the way in which an experienced dancer might teach a young dancer the steps of a dance. In practice this involves choosing a space in which to install the work, learning how to audition the ‘interpreters’ and how to teach them their paces to ensure a good installation of the work.

Here the conservation of the work centres on memory, causing us to reflect on the degree to which a key part of our work involves learning from artists how to install their work and finding ways to carry this knowledge forward. In the fast-moving world of a contemporary art museum it is easy to overlook the significance of memory as a tool for the care and management of a collection.

Interviews with artists

Every work has a different relationship to its technology, and to the space in which it is presented. Each work also has a different set of criteria when it comes to establishing what is important to preserve.

To ensure that this essential information is captured, Tate conservators work closely with the artist and/or their assistant on the first installation of their work in the gallery. They also conduct detailed interviews with the artist about the work as close to the point of acquisition as possible.


Keeping a time-based media installation working for any period of time requires careful planning. Behind the scenes there is a rota of filter, lamp and projector changes. A film or slide-based work needs daily care to ensure that these older mechanical technologies run smoothly, since they were not designed to work 70 hours a week for months on end. Tate’s conservators work closely with manufacturers to ensure that projectors can be maintained at peak performance for the duration of any display.

Investigating the chandelier in Carlos Garaicoa's Letter to the Censors 2003
Investigating the chandelier in Carlos Garaicoa's Letter to the Censors 2003

Tate Time-Based Media department

Established: (1996: first appointment) 2004

Conservators: 4

Technicians and administrative staff: 2/5ths


  • Maintaining the Tate’s rapidly growing collection of time-based media in a displayable condition and as the artist originally intended
  • Documenting artist intention via interviews
  • In-depth knowledge of the associated technology
  • Planning and preparing for future obsolescence
  • Ongoing programme of installation and maintenance for display