EMG Panel Discussion: Education Needs for Electronic Media Conservation
Funding provided by: Samuel H. Kress Foundation and Stanford University Libraries
Essays on Educational needs in Electronic Media Preservation
[to be added in the near future]
Mitchell Hearns Bishop, Getty Information Institute, Assistant Program
Chair of EMG
Exhibitions Technical Manager, San Francisco Museum of Modern
Media Preservation Librarian, Stanford University Libraries,
EMG Program Chair, Graduate of the Preservation and Conservation
Program, Graduate School of Library and Information Science,
University of Texas at Austin
Luke Gilliland-Swetland, Head of the Information Resources Group, Getty
Karen F. Gracy, Ph.D., Assistant Professor, Department of Library and
Information Science, University of Pittsburgh, Graduate of UCLA
Department of Information Studies
PCS student Preservation of Electronic Information, Graduate
School of Library and Information Sciences, University of Texan
Lead Analyst, Stanford University Libraries and Academic Information
Resources, former Officer of EMG
Digital Projects Manager, Getty Research Institute
Distinguished Teaching Professor, Art Conservation Dept., State
University College at Buffalo
Exhibitions Technical Assistant, San Francisco Museum of Modern
Director, Vanderbilt University Television News Archives
Moving Image Archivist, Milestone Film Video, Graduate of L.
Jeffrey Selznick School of Film Preservation at George Eastman
Photography and Electronic Media Conservator, Boston Art Conservation,
past Chair of EMG
Debbie Hess Norris,
Director, Winterthur/University of Delaware Program in Art Conservation
Lecturer, (representative of the University of Austin PCS Training
Program) Preservation and Conservation Studies, Graduate School
of Library and Information Sciences, University of Texan at Austin
Director of Digital Media, Berkeley Art Museum/PacificFilm Archives,
University of California at Berkeley
Senior Photography Conservator, Library of Congress
Preservation Manager, Smithsonian Institution Archives, past
Officer of EMG
Digital Asset Manager, HBO and former Chair of AMIA, Association
of Moving Image Archivists
Works on Paper, Photography and Electronic Media Conservator,
Preservation Associates, Emeryville, CA; former Chair of EMG;
Symposium Organizer Moderator
TIM VITALE: This is the Electronic Media Group's panel discussion on the educational needs for training in electronic media preservation.
In 2001, Paul Messier (former EMG-founder and Chair) and I got together to determine the next major step that EMG should take. We decided that EMG needed to explore the educational needs for training conservators in electronic media preservation.
We developed a concept that metamorphosed several times, eventually evolving into this symposium. Grant proposals were pitched, and then written. The first was for a day-long session with 20 invited guests held at a local university. That version was eventually scaled back by about half, with fewer speakers and held within an AIC Meeting (Miami), and then submitted out-of-cycle to the Kress Foundation.
About 2 months ago (April 2002), the Samuel H. Kress Foundation agreed to fund the project. For the purpose of planning an AIC session, the notification came at the very last minute, however the AIC Office knew there was a possibility of last minute funding. Many calls were made, some in the last weeks before the Miami AIC Meeting. Suddenly, the small (internal) EMG symposium turned into this marvelous group of 23 knowledgeable participants; some added even at the AIC meeting.
Now, I will attempt to describe the basics of analog and digital electronic media that are the subject of this discussion. The media list is long and is intended to be inclusive. Participants should feel free to add, correct, change or make points about the topics. Non-electronic media topics are included in the list because media preservation solutions.
1.1 There are two fundamental forms of electronic media: analog and digital.
1.2 There are two major categories of digital electronic media, and numerous analog media formats.
Cultural material can be Born digital.
Cultural material can be Migrated to digital.
conservators say, "access drives preservation."
electronic media: there are a variety of analog formats.
Analog electronic media is migrated to a digital format.
Details of Analog to Digital Conversion (ADC).
Sampling rates can range from 1 sample per second (1 Hz), to, one-per-minute, one-per-5-minutes or even longer. Low sampling rates are commonly used for recording environmental conditions with T/RH sensors (attached to data loggers), where the signal changes very slowly. An analog sound signal changes so quickly that a rate of 24 kHz (24,000 times a second) is about the lowest reasonable rate that can be used. The standard analog sample rate on a music CD is 44.1 kHz. The higher sound sampling rates are 48kHz, 88.2KHz, 96kHz, 176.8kHz and 192kHz (48,000, 98,100, etc. times a second), used on DVDs. The larger the number of samples, and steps with in each sample, the greater the "precision" of the digital recreation of the actual analog signal. On the other hand, higher sampling and bit rates require better electronic circuits and chips, and, the digital file becomes quite large because the digital representation of the signal has a huge numbers of data points.
An analog signal can be migrated to a new storage medium. And often, the first copy is quite good, but signal quality loss always occurs. The quality of the hardware, including the analog to digital converter, is critical. Signal integrity (quality) is always lost due to the introduction of "electronic noise" from the copying hardware, when a signal is copied. Each time a signal is copied, quality is lost. On the other hand, if the first copy is digital, the digital copy can be migrated with no "future" loss of quality, assuming that the correct copying protocols are followed.
Decisions made during the digitalization of analog material govern the quality of the copy. Low sampling rate and bit-depth will degrade the original analog signal. Poor quality hardware and software will introduce excess noise during digital sampling. If compression is used, the signal can be degraded to a point that is noticeable within the capabilities of human senses. Digital sampling and compression are complex topics. The three basic types of compression are: 1) lossless, 2) lossy and 3) transformations (Fourier transforms). Digital-to-digital copies have to be done without and analog intermediary, and care has to be taken not to recompress (further compress) an already compressed digital signal.
A "born" digital signal is digitally sampled in the device (from the analog world) and then recorded digitally on storage media such as a CD, DVD, hard drive or other device, as machine code. The code type is governed by the hardware (ADC), software and file format. The digital signal can be migrated to new media forever with no loss of quality if done correctly. However, if the storage media fails or the hardware that reads it goes out of use, the file will be lost. Thus, redundancy of copies (master, dup-master, use copy, etc.), equipment maintenance and file format migration are important issues.
2.4.2 Digital Video
2.5.2 Digital audio
Small amounts of the film, some in exotic gauges, are routinely found in larger cultural collections, and are thus often neglected as "too difficult a problem." If such a general collection has just a "shelf or two" of film cans (reels or cores) in storage, collections managers' may not have developed their own film preservation protocols, and thus, need help dealing with these small amounts of film. Large collections of films, on the other hand, generally have dedicated preservation procedures not involving electronic media. A simple preservation solution for small groups of rapidly aging films, may be sub-zero cold storage in consumer-grade freezer chests. However, this does not help with "access" to those artifacts. Migration to digital video can be a solution for improved access to small groups of films.
Film can be seen as part of both digital and analog electronic media streams, because film could be migrated to analog video for use by scholars and researchers in-house, to compressed digital for web access and to low-compression digital formats (D-1, DigiBeta and DVCPRO) for preservation (D-1 is chroma compressed 4:2:2; Sony Digital Betacam is compressed 2:1 at 4:2:2 chroma compression).
Many consider film a hybrid because it is traditionally the high resolution source (original) material for commercial video and television releases. Seen on a larger scale, film is just one of many incarnations of moving-image formats.
2.6.2 Slides and sheet film positives
2.6.3 Sheet film negatives
2.8.2 Imaging for preservation and access
2.8.3 Imaging for documentation
Imaging for electronic restoration
If film is to be migrated to digital solutions for improved "access," via the web, or preservation at high resolution, cold storage is the ideal interim holding solution. Since migration can be a costly (requiring fund-rasing) and is slow process, and because most film held by cultural institutions is nearing the end of its dye or film base life, sub-zero cold storage is the ideal way to maintain film almost unchanged over periods of 25-100 years, until migration can occur.
Device Repair and Restoration
When I consider this list, I'm struck by how much we need to know about its components. It is a very large body of knowledge. It would seem that "training program" solution is needed. In the beginning of the education process, imparting just the basic knowledge on all these topics will be complex and time consuming process requiring multiple specialists. In the Conservation field, this scope of information is traditionally accomplished through graduate-level training programs. Portions of this complex information could also be addressed through week-long workshops or semester/academic-quarter sessions.