Electronic Media Group

AIC Annual Meeting 2002, Miami

Monday, June 10, 2002
9:00 - 12:30

H o m e  |  A b s t r a c t s  |  L i n k s  |  R e s o u r c e s

Related items of interest:

Miami Meeting Program, Sunday, June 9, 2002

Abstracts from past EMG & EMSIG Meetings



EMG Panel Discussion: Education Needs for Electronic Media Conservation


Funding provided by: Samuel H. Kress Foundation and Stanford University Libraries


Page 1

Introduction to Discussion
The Basics of Electronic Media
List of Electronic Media Materials and Preservation Protocols

Page 2

Beginning of Discussion

Essays on Educational needs in Electronic Media Preservation [to be added in the near future]
Anne Gilliland-Swetland (UCLA)
Howard Besser (UCLA NYU)
Henry Lowood (Stanford)


Mitchell Hearns Bishop, Getty Information Institute, Assistant Program Chair of EMG

Steve Dye, Exhibitions Technical Manager, San Francisco Museum of Modern Art

Hannah Frost, 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 Conservation Institute

Karen F. Gracy, Ph.D., Assistant Professor, Department of Library and Information Science, University of Pittsburgh, Graduate of UCLA Department of Information Studies

Marlan Green, PCS student Preservation of Electronic Information, Graduate School of Library and Information Sciences, University of Texan at Austin

Walter Henry, Lead Analyst, Stanford University Libraries and Academic Information Resources, former Officer of EMG

Sally Hubbard, Digital Projects Manager, Getty Research Institute

Dan Kushel, Distinguished Teaching Professor, Art Conservation Dept., State University College at Buffalo

Noah Landis, Exhibitions Technical Assistant, San Francisco Museum of Modern Art

John Lynch, Director, Vanderbilt University Television News Archives

Anke Mebold, Moving Image Archivist, Milestone Film Video, Graduate of L. Jeffrey Selznick School of Film Preservation at George Eastman House

Paul Messier, Photography and Electronic Media Conservator, Boston Art Conservation, past Chair of EMG

Debbie Hess Norris, Director, Winterthur/University of Delaware Program in Art Conservation

Karen Pavelka, 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

Richard Rinehart, Director of Digital Media, Berkeley Art Museum/PacificFilm Archives, University of California at Berkeley

Andrew Robb, Senior Photography Conservator, Library of Congress

Sarah Stauderman, Preservation Manager, Smithsonian Institution Archives, past Officer of EMG

Linda Tadic, Digital Asset Manager, HBO and former Chair of AMIA, Association of Moving Image Archivists

Tim Vitale, Works on Paper, Photography and Electronic Media Conservator, Preservation Associates, Emeryville, CA; former Chair of EMG; Symposium Organizer Moderator


Introduction to Discussion

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.


The Basics of Electronic Media

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.

1.2.1 Cultural material can be Born digital.
The material has never seen paper, film, magnetic tape or other storage medium. The artifact is only digital. It resides somewhere on a hard drive or some storage medium. Examples are: websites, e-mail, digital images, text files, and a variety of digital library or archive objects.

1.2.2 Cultural material can be Migrated to digital.
Often this migration is for the purposes of preservation, but access is also a very common reason. Migrations for access-only can use heavy signal compression, rather than assuring the highest fidelity to the original as possible. Analog video is often migrated to digital video, most digital video is higher quality and resolution than the best analog video. Examples of migration for access are collections of 1) still film negatives, 2) color slides, 3) glass-plate negatives that have been printed for the first time (so you can see the images or determine whether you've got images in your collection) and 4) B and color prints without original negatives/slide in the collection. Many conservators say, "access drives preservation."
If you can get a collection out in front of the public, then the collection becomes important. A collection that may have gone unnoticed or under appreciated becomes valuable and is cared for because it was made available (digitally).

1.3 Analog electronic media: there are a variety of analog formats.
Analog formats are characterized by a continuous electronic signal with finite continuous variability. Examples range from the earliest Edison sound recordings to modern audio recordings on vinyl (records) and magnetic tape, and, end with video formats that range from 2" quad and 3/4" U-Matic to the ubiquitous helical-scan 1/2" VHS format.

1.3.1 Analog electronic media is migrated to a digital format.
Analog is migrated to digital by (1) sampling the continuous electronic signal at a sampling rate and then (2) scaling the sample within a series (digital) steps determined by the number of bits (8, 12, 14, 16 and 24 bits) in the analog to digital converter (ADC).

1.3.2 Details of Analog to Digital Conversion (ADC).
The common 8-bit sample has 256 steps (255 steps and zero). If the continuous electronic signal has a range of 0 to 5 volts, each of the 256 steps would be multiples of the 0.0195 volt (0.02V) step height. A problematic signal could be digitized poorly. If the signal stayed between 0.10 and 0.20 volts most of the time, rather than ranging continuously over the 0-5 volt range, but did ranged up to the full 5 volt sometimes, the bulk of the digital sample would not have good precision. This is because most of the signal would only have 5 digital steps (0.02V each) describing the predominant 0.1 V range, even though the full range of the sample would be captured by the process. In the following, a higher bit rate would be desirable, so that the small range of the predominate signal would have a greater number of digital steps. Audio signals are routinely Digitized at 12-bits, 16-bits or 24-bits, where there are 4096, 65,536 and 16,777,216 digital steps respectively, as opposed to the 256 steps in an 8-bit sample.

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.


List of Electronic Media Materials and Preservation Protocols

2.1 Internet
The full Internet is archived by Brewster Kahle's Internet Archive. Their robots and spiders make a complete circuit of the Internet every three months with about 120 Terabytes of information (as of mid-2002).

2.2 Website

2.3 e-mail
2.3.1 e-mail in ASCII-text
2.3.2 e-mail in different forms, such as flavors of HTML or XML
2.3.3 e-mail with attachments

2.4 Video
2.4.1 Analog Video
See the Video Format Guide at the Vidipax Website, under Services.

2.4.2 Digital Video

2.5 Audio
2.5.1 Analog audio
See Audio Format Guide at the Vidipax Website, under Services.

2.5.2 Digital audio

2.6 Film
2.6.1 35mm, 16mm, 8mm, Super 8 and all other gauges of motion picture film:
Increasingly, preservation work on film is done with digital (imaging) tools, after digitalization of the visual information (frames) at the highest affordable resolution. Following digital preservation, the final product is often converted back into film for presentation.

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

2.7 Text files
2.7.1 Plain ASCII text files
2.7.2 Formatted text files (MS Word .doc; WordPerfect .wpd; RTF, rich text format; XLM marked-up text file; etc.)
2.7.3 Formatted text with images and other inclusions such as images, video, etc.

2.8 Digital image
2.8.1 Artwork
Photography is the process of reproducing a image. In the past, photography has been done, largely, using the chemistry of silver salts and photographic dyes. Photographers are finding that digital technology gives them greater control over all phases of the imaging process. Some artists and designers see film as only one stage in the evolution of the two-dimensional representation of three-dimensions.

2.8.2 Imaging for preservation and access

2.8.3 Imaging for documentation

2.8.4 Imaging for electronic restoration
This category has bothered some people because they see imaging-for-restoration competing with traditional conservation practice, at the bench. There are preservation clients that can't afford a $1000-3000 bench treatment on their structurally or visually damaged artifact. They do, however, still want to use the image. Spending $300-500-800 on digital imaging and electronic restoration of the damage can be to their economic advantage. An artifact with self-adhesive tape, degrading accretions or other critical conservation needs would always have those issues treated prior to electronic restoration, or the process would not be preservation. Proper storage of the artifact after digital capture is critical because it is the original, the digital version is only a copy.

2.8.5 Facsimile
If an artifact is sensitive to light, or if the owner intends to put the work on display indefinitely, a digital facsimile is a viable preservation tool. Proper photography, capturing artifact texture, at high digital resolution is critical for the process. Output on a variety of paper types is possible, depending on the intended use and life of the digital surrogate.

2.9 Installation Art
There is often an electronic component in installation art, such as a audio track, or a single/multiple video channel within a full installation that may include three-dimensional artifacts and "chemistry-based" photographic images.

2.10 Presentation Art
The presentation of an artwork by an artist, or the video documentation of the event, may be a fully electronic presentation or it may contain single or multiple audio and/or video channels within a larger work. A script or story board, along with 2D and 3D artifacts, are generally also part of the artwork.

2.11 Games
Electronic games, "video games," are born digital. Game preservation is being driven by game designers and their dedicated users who wish to play a games on newer operating systems (OS) or on a different platform (Unix, Linux, Windows, MacOS, Amiga, XBox, PlayStation, etc.). Platform and OS emulation is being done routinely; often on an open-source basis.

3.0 Cold Storage
Cold storage is part of electronic media preservation because cultural materials (video and audio tape) can often be saved temporarily in cold storage until a solution, or funding, is available. Film is best held in (sub-zero) cold storage.

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.

3.1 Electronic Device Repair and Restoration
A significant limiting factor for the long term preservation of electronic material is availability of equipment to play back the storage medium (tape, diskette, CD, DVD or hard drive). Equipment to play VHS tape may be around for some time, but units to play 3/4" U-Matic tape are becoming hard to find. Today's desktop no longer have 5.25" diskette drives common 10 years ago; 3.5" diskette drives are becoming rare (e.g., Apple), being replaced by CD-ROM and DVD drives. Sony has ended is small output of Betamax (2000 units sold in 2002, largely in Japan) just recently. Quad tape equipment goes out of adjustment in just a few months, requiring knowledgeable technicians, which are quickly dying. VTR rubber belts and drive wheels seldom last more than 5-10 years, often far less. Replacement belts and wheels are still being made for late-model equipment, but older equipment need substitutes or newly manufactured recreations.

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.

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