Photos were taken by Luke Hones, except where captioned.

Special thanks to:

The Electronic Media and Film Program at the New York State Council on the Arts for their support of this manuscript

Charles Bensinger for permission to reproduce illustrations and photographs from The Video Guide, and thank you for your care in creating The Video Guide, an essential tool for remastering half-inch open reel.

Thanks also to:
The Experimental Television Center (experimentaltvcenter.org), and its supporters including the Electronic Media and Film Program at the New York State Council on the Arts, the Statewide Challenge Grant Program, the Media Arts Program of the National Endowment for the Arts, The Andy Warhol Foundation for the Visual Arts, the New York Foundation for the Arts, the Media Action Grant Program of Media Alliance, by corporate support from Dave Jones Design and Black Hammer Productions and by the contributions of many individual artists.

Funders of preservation and heritage projects at BAVC, including Pamela and Richard Kramlich, the National Endowment for the Arts, the California Arts Council, the San Francisco Foundation, the Pew Charitable Trust, the Andy Warhol Foundation, and NAMID.

The board and staff of Artists' Television Access (atasite.org) and the Bay Area Video Coalition (bavc.org).
 

Editors Sherry Miller Hocking and Mona Jimenez
 

"Without a consideration of the contributions of video pioneers...any history of American television, not to mention recent American social history, will be incomplete, distorted."

-- Deirdre Boyle, historian and educator, testifying at a 1996 hearing for the Report on the Study of American Television and Video.

 

Beginning as early as 1965, with the establishment by the National Endowment for the Arts of the American Film Institute with its mission of preserving our heritage of film and television, the need for saving our moving image works has been clear. Also during that decade, representatives of moving image archives originally known as the Film and Television Archives Advisory Committee (F/TAAC) began to meet. By 1990 F/TAAC changed its name to the Association of Moving Image Archivists (AMIA) which today serves as an important resource for preservation information. While progress has been made on some fronts, notably in the preservation of popular commercial film and television programming, independently produced video works remain largely neglected and in need of rescue.

In the late 1960s the introduction of relatively low-cost, portable video production equipment allowed us to create videotapes outside the strictures of the commercial broadcast world. Although we took up the new technology with enthusiasm, and created many works of originality and passion, we failed to carefully consider the lifespan of the tapes themselves, or the place of the work and its practitioners in history. Indeed, we celebrated the aesthetics of "real time", of "electronic" art, and took pride in the fact that the tools allowed us to erase and re-record over the tapes many times. The democratic and egalitarian spirit of the age called into serious question the concept of the precious art object.

Videotape was never intended to be an archival medium; while the manufacturers themselves disagreed about the lifespan of videotape, all agreed it was finite. As videotapes age, they begin to break down physically; as deterioration progresses, the tapes cannot be played back and the images are unreadable. In some cases the tapes will fail catastrophically. The collective memory of our culture, and the history of independent electronic media reside on a medium which was never intended to be permanent.

Early production work was done by individual artists, and by groups and collectives, often with the support of public agencies or private foundations. Small media arts and cultural organizations now find themselves in the role of de-facto stewards of collections of aging tapes; significant collections are also held by individuals, who also may lack the resources and support to maintain them. The collections themselves are located in a wide variety of places around the country including individual homes, libraries, museums, media arts centers, artists' spaces, universities, non-profit distributors and public television stations. The storage and care the work receives is often inadequate. The demands the collections place on smaller organizations far exceed the financial resources available, or the staff and expertise required to address the problems the tapes pose.

Because we have no union catalog, preservation work may not be performed efficiently or effectively. It is difficult to determine how many copies of an original independent work exist, who holds the best surviving copy, or what the condition of each copy might be. Slim resources may be wasted in remastering efforts which duplicate that already done by others, or preserve a copy which not the best of the extant copies.

These independent works are educational, cultural and historic resources which illuminate our shared past. Because many of the tapes are unplayable, the work is not accessible. Scholars, historians and others are unable to view these tapes which represent a major cultural and historical legacy. The preservation and increased accessibility of these tapes will advance research into our culture and society, will enhance educational scholarship and provide enriched public programming opportunities.

Each year more tapes deteriorate, some irreparably. The obsolete equipment used to create the work and necessary to its viewing and preservation is now difficult to find and almost impossible to maintain. Many early practitioners have moved on; many early groups disbanded long ago. Memories are hazy, and paper records lost or destroyed.

Thirty-five years later we find that our field is in danger of misplacing its own history. Our society is in danger of losing these cultural and historical documents.

While much remains to do, a glance at the list below testifies to our hard work.

In the 1980s under the leadership of Debby Silverfine, then the Director of the Electronic Media and Film Program at The New York State Council on the Arts, a support category for preservation activities was established. Throughout the decade many organizations and individuals engaged in efforts to preserve collections. Among them were the Andy Warhol Foundation, Anthology Film Archives, Bay Area Video Coalition, Downtown Community TV Center, Electronic Arts Intermix, Experimental TV Center, Intermedia Arts of Minnesota, The Kitchen, Museum of Modern Art, Pacific Film Archives, Video Data Bank, Tony Conrad, Bob Harris, Woody and Steina Vasulka and many others.

In 1991 the Museum of Modern Art hosted a Symposium on Video Preservation, organized by Media Alliance and the New York State Council on the Arts.

In 1992 the National Alliance for Media Arts and Culture established a national Video Preservation Task Force.

In 1993 Media Alliance published Deirdre Boyle's Video Preservation: Securing the Future.

In 1994 the Upstate Cataloging Project met in Rochester with Margaret Byrne, Director of the NAMID project of the American Film Institute. Representatives included the Experimental TV Center, Hallwalls, Syracuse University, and Visual Studies Workshop. This resulted in the adopting of a NAMID-compatible template, designed to allow conversion to USMARC. Media Alliance worked hard to underscore the need for compatible cataloging, encouraging the continued refinement and use of the template.

1995 Bay Area Video Coalition opened the first non-profit remastering facility for 1/2" open reel tape, under the direction of Luke Hones. Arthur Tsuchiya, then in the Media Program at the national Endowment for the Arts, was instrumental in advancing the cause of preservation of independent video.

In March 1996 the Library of Congress held hearings in Los Angeles, New York and Washington, DC for the Study of the Preservation of Television and Video, conducting a national needs assessment and resulting in a set of recommendations in areas such as cataloging, cleaning and remastering, education and storage.

Also in 1996 BAVC held Playback 1996: Video Preservation Roundtable with assistance from Media Alliance. Funded by the Getty Foundation and the Andy Warhol Foundation for the Visual Arts the international symposium was the first to build alliances between the media arts and art conservation fields.

In 1998 two significant documents were published. Magnetic Media Preservation Sourcebook, edited by Mona Jimenez and Liss Platt was published by Media Alliance. Playback: A Preservation Primer for Video, edited by Sally Jo Fifer, Tamara Gould, Luke Hones, Debbie Hess Norris, Paige Ramey and Karen Weiner, was published by Bay Area Video Coalition.

Also in 1998 the Experimental TV Center organized Video History: Making Connections, a conference concerning the links between early media history and contemporary practice, held at Syracuse University. Bringing together over 250 media makers active in the 70s and those artists working today in new media and interactive technologies, the conference celebrated our history and established new partnerships with cultural and educational institutions across the country.

In 1999 Independent Media Arts Preservation (IMAP) was established, with support from the New York State Council on the Arts and the Rockefeller Foundation.

In 2000 BAVC organized TechArcheology: A Symposium on Installation Art Conservation, held at the San Francisco Museum of Modern Art, and supported by the Getty Foundation.

In 2001 Preserving the Immaterial: A Conference on Variable Media was held at the Solomon R. Guggenheim Museum. The focus of the conference was the museum's Variable Media Initiative, which proposed radical new solutions to the contested issues of new media preservation

In 2002 an On-Line Media Preservation Salon was hosted by NAMAC, facilitated by Jim Hubbard and Mona Jimenez. Panelists include Sherry Miller Hocking (Experimental Television Center), Karan Sheldon (Northeast Historic Film), Toni Treadway (International Center for 8mm Film), Stephen Vitiello (The Kitchen), Heather Weaver (Bay Area Video Coalition), and others

The symposium Looking Back/Looking Forward, intended as a working session where artists, media arts staff, conservators, and technical experts focuses on the physical preservation of independent electronic media, held May 31 and June 1, 2002. The symposium is organized by the Experimental Television Center (ETC) in association with Independent Media Arts Preservation (IMAP), Bay Area Video Coalition and the Electronic Media Specialty Group of the AIC (American Institute for the Conservation of Artistic and Historic Works). Looking Back/Looking Forward is hosted by the Downtown Community Television Center and is made possible with public funds from the Electronic Media and Film Program of the NYS Council on the Arts, and assistance from IMAP and Dave Jones Design. The symposium is organized by Sherry Miller Hocking, Assistant Director of the Experimental Television Center, and independent consultant Mona Jimenez.

We face many problems. As we craft solutions, we need to forge partnerships with a varied constituency. We should engage professionals working in other media in extended conversations, to identify models which may be successfully transposed to the media arts field. Collaborative strategies will help us make effective use of scarce resources. Successful proposals will sharpen our vision and deepen our commitment.

The Recommendations for Safeguarding and Preserving the American Television and Video Heritage, from A Study of the Current State of American Television and Video Preservation, published by the Library of Congress in 1997 provides a national plan. The recommendations offered in this report, as well as by other preservation organizations such as AMIA and IMAP include:

• Acknowledging our responsibilities in caring for these materials

 

• Research into storage archives for video

 

• Maintenance and cataloging of key archives, using compatible templates

 

• Sharing of information concerning collections to prevent duplication of preservation efforts

 

• Research into need for additional remastering facilities

 

• Research into archival and technical matters affecting moving images

 

• Establishment of additional public and educational programs to raise public awareness

 

• Development of more coalitions to invite into the conversation those who have not been involved - marginalized groups, small organizations and individuals

 

• Increased support from a broader base of funders

 

There are many resources available on the Web for those interested in moving image preservation. Here are a few places to begin.

Association of Moving Image Archivists
AMIA is a non-profit professional association established to advance the field of moving image archiving by fostering cooperation among individuals and organizations concerned with the collection, preservation, exhibition and use of moving image materials. AMIA provides a Listserv for active exchange of ideas and help; an annual conference as well as workshops and public programs; and newsletter.

Bay Area Video Coalition
Visit the Remastering Facility

Conservation OnLine
A project of the Preservation Department of Stanford University Libraries, this site offers a full text library of conservation information, covering a wide spectrum of topics of interest to those involved with the conservation of library, archives and museum materials.

Experimental Television Center Video History Project
In 1994 the Center organized the Video History Project, a multi-dimensional approach to reclaiming our past. The Video History Website is a dynamic vehicle for the creation and dissemination of an inclusive media history, encouraging participation by a wide range of people including early pioneers as well as contemporary practitioners. The structure depends on 9 databases which contain a total of about 2500 records relating to people, tools, groups, and an extensive bibliography. The Preservation area contains several resources. "Video Preservation: The Basics", written by Mona Jimenez and Sherry Miller Hocking, is an introductory primer on electronic media preservation with information on topics ranging from storage to cleaning, copyright to remastering, as well as glossaries and extensive links. "Reel to Real: A Case Study of BAVC's Remastering Facility" by Luke Hones, and well as several early texts on preservation are also available.

The Image Permanence Institute at Rochester Institute of Technology
The Institute is a University-based nonprofit research laboratory devoted to scientific research in the preservation of visual and other forms of recorded information. IPI offers research, testing, publications, consulting and educational seminars.

IMAP
IMAP is a service, education, and advocacy consortium, organized in 1999 to ensure the preservation of independent electronic media for cultural and educational use by future generations. IMAP is especially interested in supporting the preservation of works reflecting the early history of independent media. IMAP participates in national and international forums on preservation serves as a central place for information on issues of preservation. Through technical assistance, training, and by developing replicable models (like the IMAP MARC for FileMaker Cataloging Template), IMAP helps non- profit organizations and artists/producers care for and preserve their electronic media collections.
 
 

"The American television and video heritage is now at a crossroads. One direction leads toward catastrophic losses of film and videotape, with the likely exception of studio and network programs in corporate archives that can be recycled for new income. Another direction leads toward the managed preservation of extant television and video materials that bear an important relationship to American history and culture regardless of their reuse potential or monetary value."

- Television and Video Preservation 1997: A Study of the Current State of American Television and Video Preservation, Volume 123

 

Sherry Miller Hocking
February 2002
 

The EXPERIMENTAL TELEVISION CENTER was founded in 1971, an outgrowth of a media access program established by Ralph Hocking at Binghamton University in 1969. The Residency Program offers self-directed creative residency opportunities to media artists from around the world, to support the creation of new works. Deadlines are July 15th and December 15th. The Grants Program offers Finishing Funds (deadline March 15) to NYS's media artists, and Presentation Funds (on-going deadline) to organizations in the State for in-person appearances by film and media makers. We also provide Technical Assistance (quarterly deadlines) to media organizations in NYS for a variety of needs. Video History Project is an on-going research initiative which documents the emergence of video art and community television, and makes resources available on the Web. The Center offers sponsorship for artists' projects, providing support and fiscal and administrative management services. We also serve as an information resource for artists. The Center's programs are supported by the contributions of artists, by public funds from the New York State Council on the Arts and the National Endowment for the Arts, by The Andy Warhol Foundation for the Visual Arts, the State-Wide Challenge Grant Program, and the Media Action Grant program of Media Alliance. Corporate assistance provided by Dave Jones Design and Black Hammer Productions.
 

• The trouble with videotape
• BAVC rises to the challenge
• Entering the preservation landscape
• A remastering center emerges

 

The trouble with videotape

From the moment of its manufacture, videotape begins to break down. Videotape is composed of magnetic particles applied with a binder to a polyester strip. The tape is stable only as long as the binder performs well. Manufacturers have never guaranteed tape stability for more than a decade.

Tape is only stable for a short while and is subject to harsh treatment during use. It is dragged through a tape path, across a spinning head, and wound around a spool. Depending on the maintenance of the tape machine, videotape often ends up with crinkles, creases, stretches or tears.

There are additional dangers. Videotape attracts debris, such as air-borne dust. Good storage practices are essential to maximize "shelf life." Caretakers must be concerned about humidity, temperature, storage medium, storage orientation, proximity of magnetic equipment (such as stereo speakers) and other materials.

Finally, the information on videotape can be retrieved - seen and heard - only through the use of the right playback machine and equipment. This equipment must be well maintained by a maintenance engineer. Yet video equipment is continually becoming obsolete. If videotape has been recorded in a format that has not been used for several years, working equipment and equipment replacement parts will be difficult to find. Compounding the problem, as video technology changes, it is a rare technician or engineer who will work with or repair equipment that is not "state-of-the-art."

In 1992 BAVC faced these problems - deteriorating videotape, no equipment, no parts, no technicians, and no engineers - as we considered remastering 1/2" open reel videotapes. At the time, I was the Director of Research and Development at BAVC, and Sally Jo Fifer was the Executive Director. The commercial vendors who performed the work and our technical consultants all outlined these problems.. And this picture has proved to be very accurate.

Despite these warnings, BAVC began to remaster obsolete tape formats, specifically "skip field" and EIAJ 1/2" open reel, in 1994. From the beginning it has been the intent of BAVC and many in the media arts field that the remastering work BAVC does, and the vision of the remastering work that can be done, would be shared by a broader pool of organizations and technicians. This paper serves as a first step to make good on this promise.
 

BAVC rises to the challenge

Why then did BAVC move forward with researching and developing a video remastering program, a seemingly impossible task? There were four important reasons for BAVC.
 

• First, the need in the media arts and independent video community was tangible. Steve Gong from Pacific Film Archives raised the idea of remastering to BAVC at the 1992 meeting of the National Alliance for Media Arts and Culture (NAMAC) in Portland, Oregon. This was shortly after a 1991 symposium on video preservation held at the Museum of Modern Art in New York City, organized by Media Alliance in partnership with the Electronic Media and Film Program of the New York State Council on the Arts.

The need for action was clear from our conversations with Steve, and reinforced by Deirdre Boyle's article on the symposium "Video Preservation: Insuring the Future of the Past" (The Independent, 1991). You can read the article in the Resources>Written Word>Bibliography section of the Video History site. It was clear that significant artworks and documents concerning art history were on 1/2" open reel and were largely unavailable. In 1993, the symposium and its findings were later documented by Deirdre in the monograph Video Preservation: Securing the Future of the Past published by Media Alliance.

There were a number of other articles from within the media arts community, some of which I was unaware at the time. Historically significant articles related to video preservation are published on the Video History Project web site, a project of the Experimental Television Center. See the sections Tools - Texts and People - Texts

• Second, traditional moving image preservation professionals seemed to consider videotape a lower priority than film. In the early 1990s film preservation, was concentrated on Hollywood classics. The positive marketing of film preservation had also succeeded in increasing general public awareness of the need for saving films and of the organizations doing this work. The publicity and awareness of need had begun to trickle down to avant-garde or experimental film.

Independent media and video art were largely ignored, as were commercial and public television programming. . With the exception of the Pacific Film Archives, preservation organizations expressed little interest in restoring video; the video that interested BAVC and the media arts community was even more marginalized.

Despite the culturally significant role of electronic media in the last quarter of the 20th Century, video and sound recordings are often considered "throw-away" documents. Even in news gathering organizations, tapes are often recycled, with new news recorded over old news. We know that history is constructed by what historians can piece together from the documentation that survives. Through remastering services, BAVC and other media arts groups will keep a window open on the people, actions and discussions from particular places and times in the previous century.

• Third, it wasn't clear whether any other media organization aside from BAVC intended to offer a remastering program. There were valid debates in the archival and media arts communities about cleaning techniques and preservation formats, and these debates were taking center stage. Because of the expense involved in any serious effort at remastering, it was a risky endeavor to begin a program without a resolution of these issues. However, at BAVC we thought we had the advantage of being outsiders to the debate. The organization also had technical proficiency, and a tendency to take risks when needed.

• Fourth, it was felt that the remastering program would enhance BAVC's image as a technology leader. We felt that if BAVC could develop a remastering program that could be run efficiently and meet the highest standards, we could provide a needed service for the media arts community, provide BAVC with another income stream, and market our efforts to funders.

At the time, BAVC had been in the process of developing a strong facility for several years. BAVC had long term relationships with some of the best maintenance engineers in the Bay Area, and BAVC's equipment was professionally installed and well documented. The facility had a reputation for being a good first stop for technicians interested in working in the high-end video/computer graphics industry.

For foundations and individual donors, BAVC wanted to display the ability to think outside the box. BAVC's idea for the remastering program came at the same time that many arts organizations were exploring program expansion into new technologies such as multimedia and CD-ROM production. BAVC advocated a thoughtful and measured approach to the "technology of the moment", and wanted to emphasize our role as a leader in the field, with a solid understanding of the subtleties of technology development.

BAVC was also approaching new technology manufacturers for support, and defined ourselves as a center that could present their products in the best possible light. We argued that BAVC was a good site for their products not only because of its position as a nonprofit technology center, but also because BAVC had professional staff that was capable of providing leadership on such thorny technology issues as video preservation. We hoped that preservation would be a cornerstone on which we could build a new technology facility.

However, before BAVC began transferring its first tape, we had to address the politics of remastering videotape.
 

Entering the preservation landscape

I began to call tape manufacturers and remastering specialists to get a sense of best practices. Some were very open about their work; others were concerned about releasing proprietary information. Soon I began to get calls from other professionals in the business curious about BAVC's intentions. In some cases I felt like I was being "warned off," but I always made it clear that BAVC's course was set: we were committed to setting up a 1/2" open reel remastering facility.

An early attempt had been made to call our fledgling center the "National Center for Video Preservation" which created a stir with a national film preservation organization. While there was no evidence that the organization had any interest in physically preserving video, BAVC could not expect funding by initiating a branding war. After Sally discussed the issue with the National Endowment for the Arts, we settled on referring to our center as a model remastering center. The term "model" also allowed us to distinguish BAVC's center from remastering facilities that chose not to share their techniques. We believed that information-sharing was important.

BAVC also wanted to meet with staff from Media Alliance who had encouraged the discussion among facilities on the east coast, to introduce ourselves. While BAVC had the advantage of being somewhat outside preservation debates, we felt we could easily become unwelcome interlopers if we didn't proceed carefully. We met Mona Jimenez of Media Alliance for the first time at an NEA conference in Chicago in 1994. At that point we had done some tests with a borrowed 1/2" open reel machine from the Optic Nerve collective, but it was still a few months before we acquired our first machines, in trade for remastering services.

After meeting with Mona, it was clear BAVC could no longer act independently. Up to that time, BAVC had been a "local" San Francisco media arts center bent on providing services and differentiating itself from Film Arts Foundation and other local media arts centers. BAVC's vision was to capitalize on opportunities to benefit BAVC's growth; we focused on our strengths and pursuing projects where we could be successful. Mona made it clear that if we intended to do the work of remastering, our obligation to the larger field and to media producers would deepen. Our vision would need to go beyond BAVC's bottom line and organizational concerns.

In addition to Media Alliance, BAVC worked to develop relationships with key organizations and individuals such as Electronic Arts Intermix (EAI), Video Data Bank, and Arthur Tsuchiya, who at the time was in the Media Arts Program at the NEA. In order to develop a funding and client base, we needed to be represented at meetings of archivists and librarians. We began to attend events organized by the Association of Moving Image Archivists (AMIA) and the American Library Association (ALA). We also visited the American Film Institute to connect with the staff working on the National Moving Image Database (NAMID), a cataloging project.

With the basic groundwork in place, BAVC applied for and was awarded a Challenge Grant from the NEA in 1993 to develop the model center. Sections of the original proposal "The National Video Preservation Center - A Brief Overview" is on the Video History site Resources>Groups>Bay Area Video Coalition. At this point, there was no turning back. The NEA challenge was matched in the years following with funds from the Andy Warhol Foundation for the Visual Arts, the San Francisco Foundation, NAMID and the California Arts Council.
 

A remastering center emerges

In the fall of 1994 I visited Intermedia Arts  in Minneapolis, Minnesota, a media arts center with an historic regional video collection in need of preservation. Director Tom Borrup took me up to the attic and showed me four 1/2" open reel machines. I loaded them into my car, signed an agreement for BAVC to transfer 100 tapes in exchange for the decks, and drove home to San Francisco. The remastering center's first transfers took place shortly afterwards and were delivered to the Minnesota Historical Society, which houses the collection.

The remastering center was developed over time. In the beginning I tested and set up the basic equipment configuration, heeding any advice I could glean from engineers at Ampex, 3M, Sony and commercial remastering facilities. The first few remastering jobs, in particular the Minnesota Historical Society and the Gay and Lesbian Center at the San Francisco Public Library were not documented, but BAVC's Debra Finucane, Preservation Technician, and Grace Lan, Facility Manager, soon developed the first documentation sheets for remastering projects. Debra and Grace also were instrumental in establishing a standardized administrative workflow, essentially transforming a research center into a business center. The administrative workflow continues to be improved.

Perhaps because of the necessary evolution into a business center, the important work of research and development, evident early in the project, has fallen by the wayside. BAVC has an established remastering process, and has no funding to research, modify or develop other methods. BAVC technicians Jonathan Selsey, Preservation Technician, and Heather Weaver, Senior Staff Editor, see this as a real weakness that must be addressed in any future development of remastering systems.

We had no original technical documentation on hand, so technical development for the facility was done without technical manuals for the tape machines. We relied on two resources in our efforts to set up and maintain the equipment. One was a well illustrated book from that era, Charles Bensinger's Video Guide (Video-Info Publications, 1979.) In his acknowledgements, Bensinger writes: "Video being such a visual subject, it seemed desirable to utilize as much visual material as possible." The illustrations are numerous and give a very complete view of the equipment of that time. Bensinger's description of the 1970s state-of-the-art technology guided my understanding of what I needed to know. The Video Guide substantially cut down on my trial and error.

Another resource was the engineer Ken Zhin of Merlin Engineering of Palo Alto, who I located through Deirdre Boyle's Video Preservation: Securing the Future of the Past. Ken works on both obsolete tape machines and on the tape cleaning machine that BAVC uses, and was very helpful throughout the development of the center. Other key information, as noted below, came from Sharon Grace of the San Francisco Art Institute, and from NASA Publication 1052: Magnetic Recording for the Eighties.

In the beginning we did not know it would require seven years to take this first step. We underestimated the complexity of the challenge of video preservation. During this time, discussions concerning appropriate preservation formats, cataloguing, gatekeeper selection processes and video art documentation dominated, while discussion of remastering took a back seat. Each of these topics is Very complex and full of controversy within the field. Remastering was not emphasized perhaps because 1) it was happening at BAVC and other places; and 2) it is a rhetorical/technical quagmire where every step is open to a prolonged debate.

At the time the remastering center was being developed, electronic communications tools like email and the Web were not widely used. Since t that time, AMIA and Independent Media Arts Preservation (IMAP) have provided important information sharing on preservation issues through their listservs. Video Preservation - The Basics (www.experimentaltvcenter.org/history/preservation/preservation.html), part of ETC's Video History site, is another great resource for the media arts community.

However, there is little provocative or new information about remastering. Over the last several years some archives have asked me to help them set up 3/4" U-matic transfer systems, and I've heard from some technicians about small projects they've attempted. However, as far as I know BAVC is the only non-profit in the US doing ongoing work remastering 1/2" open reel.

The following description of BAVC's remastering center - its equipment, system design, some common problems and solutions, and future vision - will be very specific and technical. .
Hopefully, the description will accomplish three important goals:
 

• Provide a recipe for creating a video remastering transfer center
• Identify parts of the process that need further research and development
• Give others a head start in designing and developing remastering services

I provide this recipe knowing full well that, for some, it will not taste like the "remastering center Mom used to make." Like a recipe, you should use the general idea and develop your own ingredients list and process.

This paper deals primarily with the transfer of 1/2" open reel and early 3/4" U-matic tapes. It assumes basic knowledge on analog production processes and equipment. Sections of the Video History project site, in particular the sections Tools - Texts and People Texts  have numerous articles that provide more information. "Video Preservation: The Basics" has several extensive glossaries of technical terms which will be of use. In addition, there are links to other sites with glossaries. The Preservation Area also has posted numerous historical articles on the subject.

A tape transferred in BAVC's remastering center undergoes three related processes.
 

• Preparation - whatever is done to the original tape after it is received by the facility and before it is transferred by the playback machine.

 

• Transfer - the act of copying the electronic signals from the original tape to a new tape.

 

• Documentation - the written recording of the preparation and transfer processes, as well as any important details about the original tape and tape copy. Documentation is ongoing during the above steps.

 

Each of these processes has evolved independently of the others. In the years since BAVC has offered the remastering facility, we've modified each of these processes as needs and conditions specific to each process were identified. Tape preparation using a tape cleaning machine has changed very little in the seven years BAVC has been doing transfers. The transfer process has only changed as new challenges arose with a particular tape. The area of documentation has seen the greatest change.. Our first group of transfers was not documented. As BAVC has had more contact with conservators and archivists, we have refined the process of documentation to address the concerns and needs of tape caretakers.

• Researching tape preparation
• Tape cleaning becomes the preferred method
• Using the Recortec and the RTI

Researching Tape Preparation

Our research identified four typical methods:

? No preparation
? Washing
? Baking
? Cleaning machine

Ideally, one would not need to do any preparation of the tape prior to transferring it. However, our research showed that many in the field experiences problems when playing back 1/2" tapes. Frequently the signal deteriorated within minutes into a screen of "snow", as the heads clogged. Our tests confirmed this. Even more serious than clogged heads is the danger that the tape could stick to the head drum or another part of the tape transport. Because 1/2" open reel equipment is as valuable as 1/2" open reel tapes, it is not worth taking a chance damaging the equipment. We decided that 1/2" tapes might require some preparation.

With 3/4" U-matics, transfer without preparation is often worth trying first because it may avoid running the tape needlessly. The tapes are often not as old, and thus have not deteriorated as badly. Knowing the age and condition of the tapes will help make this decision. Also, parts for U -matic equipment are more readily available than for 1/2" decks.

We determined that we would need to prepare the tapes, and went about researching the three methods. We also began to get calls offering advice.

A number of technicians reported luck with various wash solutions. Technicians from both Ampex and 3M recommended baking tapes to facilitate playback, because the heat revitalized the binder, reducing the loss of magnetic particles.

BAVC decided not to explore either of these two methods. They were comparatively labor and time intensive without being conclusively better (or worse) than other methods. BAVC was also concerned that washing and baking could damage tapes, making any future transfers impossible.

For these reasons BAVC decided to work first with tape cleaning machines, postponing any experimenting with other methods until after we had implemented the machine method.

Tape cleaning becomes the preferred method

BAVC first became aware of using tape cleaning machines through an article in its newsletter Video Networks. In 1985, Sharon Grace of the San Francisco Art Institute reported using a machine manufactured by Recortec to clean and transfer 1/2"1/2" open reel tapes. The Grace article appears on the Video History Web at Preservation- Texts. Also, Lowell Moulton, a Sony engineer and BAVC Board member, had provided BAVC with a copy of a 1982 NASA publication, Magnetic Tape Recording for the Eighties (Reference Publication 1075). It described the design elements of various tape cleaning machines. The cleaning machines had been developed primarily as a tool for maintaining data tapes, a prevalent data storage medium at the time.
 

 
 

We decided to use a Recortec machine for several reasons. Recortec had a proven track record of cleaning data and videotapes in a variety of environments, and the machine was documented in the NASA publication. The machine method was comparatively fast and the tape transports were designed for careful tape handling. Also, Recortec was located l fewer than sixty miles from BAVC in San Jose, CA.

Using the Recortec and the RTI

The tape-cleaning machine that BAVC uses, the VTE-200, has a left and right reel. Each reel can be a supply or take-up reel, because the machine can clean both left-to-right and right-to-left.

The cleaning modules are located between the two reels.
 

   cleaning modules
 
 

The module closest to the reels contains cleaning tissue on spools. The take-up tissue spool is driven by a clock motor, at a very slow speed, to prevent re-depositing debris that has already been wiped from the tape.
 
 

   slotted grids
 
 

The module of slotted metal grids resembles the grids on an electric shaver, and has a vacuum under the grids to remove debris from the tape path.
 
 

The final module is a sapphire block.
 

  sapphire block
 
 
 

In the middle of the tape transport the tape passes through a vacuum chamber.

  vacuum chamber

This chamber performs two functions.

Its most important function is to minimizes tape tension as the tape travels through the tape path. It also removes debris from the tape path.
 

The Recortec machine can be configured with different modules in different locations in the tape path. The configuration BAVC settled on was developed through experimenting with donated 1/2" open reels. Through this process the Recortec technicians noted that videotapes were often not handled as carefully as data tapes - perhaps because of the difference between the typical cleanliness of a mainframe computer room and the more casual environment of a media arts center. Therefore, it was important to choose the method that minimized the possibility of further damage to the tape, even if other methods had other more desirable characteristics, such as durability.

The Recortec cleaning machine has both a desktop and a rackmount model. Both take up a lot of space. BAVC purchased a used desktop model. A rackmount model would be preferable since the rest of BAVC's control room equipment is mounted in 19-inch racks.
How many times should a tape be passed through the cleaning path? Responding to a suggestion from a local conservator, in 1995 BAVC performed a test by running a tape through the Recortec cleaning path 20 times and transferring the tape after 1, 5, 10, 15 and 20 passes.

The results were recorded on a Betacam SP tape, and the same section of the original tape was edited in split screen, video with 1 pass on the left, video with 5 passes on the right. This split screen comparison was created for each of the passes. No noticeable degradation to the video could be detected either visually or by use of a waveform monitor. . There was also no noticeable audio signal loss.

While this experiment showed that we could theoretically run a tape through the cleaning process 20 times, time constraints seldom allow that, and it is unnecessary. One pass on the Recortec machine takes about 5 minutes. Typically 2 to 5 passes is enough to allow us to transfer a tape without playback problems.

Recortec's line of tape cleaning machines is long out of production. However, according to Lester Lee, a technician at Recortec, they still repair and re-furbish the machines, and can also help locate a used machines, or build one to the customer's specifications. They can be reached at 408-928-1480, fax 408-729-3661 or email [email protected].

A web search for tape cleaning machines reveals a number of different companies involved with tape cleaning. Appendix 12.1 contains some information about these companies.

  Recortec
 
 

Two years after BAVC began cleaning 1/2" open reel tapes we purchased an RTI 3/4" U-matic cassette tape cleaner.

At that time, RTI was the only manufacturer we were aware of making affordable U-matic cassette cleaning machines. However, our purchase of the RTI machine was made with much less research and testing. At the time we were just too busy, and we needed to quickly provide remastering services for clients with U-matic tapes. RTI makes cleaners for everything from VHS to DVCAM tapes. RTI can be reached at 847-677-3000, 800-323-7520 or 818-838-0480; [email protected].

• Format Identification and Terms
• Issues with skip field and the Sony CV-2100
• The Sony AV series
• 3/4" U-matic transfers

Format Identification and Terms

Another complicating factor in the transfer process is the need to identify the media and the playback equipment.

    Sony CV Portapak   Photo by Sherry Miller Hocking.

The first 1/2" open reel format was the CV series, made primarily by Sony.

In 1969, the AV series was introduced - the first 1/2" format engineered to an industry standard. EIAJ (Electronics Industries Association of Japan) decks were made by Sony, Panasonic and others. This standard ensured compatibility among manufacturers and permitted tapes made on one system to be played back on equipment manufactured by another company. Ideally a 1/2" remastering facility should have both CV and AV source decks.

For background on CV recording see Sherry Miller Hocking's article "An Introduction to Portable Video Systems" in the Video History site's Tools - Text section.

For identification of media, see Sarah Stauderman's Video Identification Guide and the Vidipax web site, which has both a media identification guide and guide to equipment. The LionLamb site  has an extensive and detailed survey of many early video formats. The manufacturer's specifications sheets for some of the early tools are located on the Center's Video History site's Tools area, along with images.

You may also find it helpful to browse the contents of Video Preservation - the Basics. The section "Video Terms" contains a basic technical glossary, which is helpful in understanding the problems typically encountered in tape transfers, as well as links to other glossaries on the web.

For a general discussion of how video is recorded, the Video History Website has several articles. Sherry's "Principles of Electronic Image Processing - Sync", "Principles of Electronic Image Processing - Signals", "Principles of Electronic Image Processing - Image" and "Two Texts Concerning Portable Video" will be helpful.

Issues with skip field and the Sony CV-2100

In the world of 1/2"open reel transfer, most tapes are EIAJ. However, you may encounter "skip field" or CV tapes. The formats are not compatible; a CV tape will not play back properly on an EIAJ- compatible machine. On an EIAJ-compatible deck, a "skip field" tape will play back sound correctly but video will be skewed and out of sync. While the video is present, it is out of sync. If you encounter a tape which has good audio but noisy video, then the heads on the playback deck are probably dirty.

You may encounter a tape with EIAJ recorded on one part and "skip field" recorded on the rest.

Tape players/recorders are electromechanical devices. They function by mechanically pulling a magnetic tape over magnetic heads.

There are separate heads for audio recording, audio playback, video recording, and video playback. There are also playback and recording heads for other signals such as control track pulses. The electronics of the tape player/recorder process signals as they pass between the tape and the input/output connectors of the player/recorder.

One of BAVC's source decks is the Sony CV-2100, a 1/2" open reel videotape player. The CV-2100 plays videotapes that are recorded with "skip-field" equipment.

The NTSC signal, the standard for video signal recording in the U.S., is made up of 30 video frames per second, each frame is constructed of 2 fields of video. There are 60 fields per second in an NTSC video signal.

Tapes recorded on "skip field" equipment have only 30 fields per second (one field per frame). A second field is interpolated by the video player's electronics. The signal will therefore play back properly on an NTSC monitor, or be sent properly to an NTSC video recorder for transfer. Video recorded on "skip-field" equipment is monochrome.

A CV-2100 offers special challenges, there is no BNC or RCA connectors for video output. What to do?

There is an 8-pin EIAJ connector on the CV-2100. This connector effectively "bundles" both input and output signals for video and audio as well as ground into a single cable. In the early 1990s, many studio monitors and video recorders still used this type of connector in the early 1990's to reduce the tangle of cables in a studio.
 

 

To send the video signal out of the CV-2100, I ordered an 8-pin EIAJ connector from Comprehensive Video in San Francisco. I cut off one BNC end of a short BNC cable and soldered the cable's conductor to pin 2 of the EIAJ connector, and the cable's metal sheathing (layer just beneath outer plastic coat) to pin 6 for a ground.

I keep this 8-pin EIAJ to BNC cable short so it is portable and functions like an adapter. A barrel connector and a longer BNC cable complete the video connection.

The audio connector on the CV-2100 is a mini plug and the signal is not +4 db. If the record machine has +4 db audio (Beta SP, Digital Beta, one inch, etc), the audio will need to be matched.

I've also had problems with video signal termination coming directly off of the CV-2100. Termination means to complete a circuit by connecting a resistive load to it. A video termination is typically a male BNC connector which contains a 75 ohm resistive load. When there are looping inputs, any unused looping input must be terminated in 75 ohms to ensure proper signal levels and to minimize reflections.

An example is a video with a close up of a human face. Directly off the CV-2100 I could distinguish few facial features. To address this, I did an experiment. I transferred the skip-field signal directly onto a 3/4" U-matic tape. On the Sony VO-9850 U-matic recorder I used, a, the video input level can be adjusted. I turned this all the way down. I then transferred from the U-matic through a time base corrector (the Sony BVT-810), again lowering the video signal.

The results astounded me. I could make out freckles and hair strands. The face was very clear and detailed.

The Sony AV series

The Sony AV-8650 is a color 1/2" open reel player/recorder that also plays back monochrome video. This video player conforms to an EIAJ standard, with video the standard 30 frames per second, 2 fields per frame. Other decks in the Sony AV series are the AV-3600, the AV-3650 and the AV-8600. The 3600 and 3650 are black and white machines. The 8600 and 8650 are color. The 3650 and 8650 are editing decks.

     Sony  8650

Most of the 1/2" open reel tapes that are transferred at BAVC are played back on this machine. BAVC has two AV-8650s.

As far as connectors go, the AV-8650 is modern compared to the CV-2100. Audio out is still a mini plug, but the video out is either a UHF or BNC connector. A UHF to BNC adapter is readily available at electronics stores such as Radio Shack.
One important feature of the AV-8650 is that the video input will also serve as a sync input. With a "sync in," you can run the video signal of the AV-8650 through a time base corrector (TBC) that is not full frame, such as the Sony BVT-810.

The audio connector on the AV-8650 is a mini plug and the signal is not +4 db. If the record machine has +4 db audio (Beta SP, Digital Beta, one inch, etc), the audio will need to be matched.

Even though the AV-8650 has a "color/BW" switch, I feel that it seldom pays to switch from color. Often tapes have several segments edited together. Some may be color and some monochrome. Unfortunately, if you leave the switch in color the monochrome image may have sparkles of false color.

The only way to avoid this is to attempt to change the color switch on the fly. Perhaps the best "workaround" is to record in color, accepting false color artifacts. If this tape is used to create a new program, the program color can be adjusted in post-production.
 

    The rewinding set-up

The two AV-8650s are mounted to provide a simple rewind station. BAVC's CV-2100 doesn't rewind tapes. We took this feature into consideration when we designed the ergonomics of the remastering center.

With 1/2" open reel decks the information is recorded on the diagonal. This is referred to as helical scan. The supply reel sits higher than the take-up reel and the tape drops in its path from the supply reel, past the video heads on its way to the take-up reel. This drop in the path as the tape is moving causes the information to be recorded on a diagonal on the tape.

 

We have our two EIAJ 1/2" open reel players mounted next to each other on the same level. With this configuration we can rewind tapes without passing them through the video player's tape path.

We put the tape to be rewound on the right player's supply reel spindle, and the empty take-up reel on the left player's supply reel spindle. Wind the end of the tape around the take-up reel and you are ready to rewind.

If you turn the left player's control lever to "REWIND", nothing will happen because there is an auto shutoff mechanism in the player's tape path. It is a metal part that resembles a paper clip. Using your right hand to provide some tension to the tape to be rewound, push on the auto shutoff mechanism. The tape should begin to rewind. It will continue as long as you push on the mechanism.

3/4" U-matic transfers

The Sony BVU-800 is a 3/4" U-matic tape machine originally designed for the broadcast market. Industrial models have part numbers that begin with "VO," the most popular models are the VO-5850 and VO-5800.While Sony also made many U-matic models for the industrial market, the broadcast models are preferred because of two significant differences. First, Sony added a visible head switch glitch in the output of the industrial U-matics. This head switch looks like 4 lines with skew errors at the bottom of the image. Also, the industrial U-matics may exhibit vertical picture rolls if address track time code is present on the tape, although an engineer can correct this.
 

U-matic machines have a BNC for video out. U-matics also have a U-matic dub input and output connector for video, essentially a precursor to the S-Video connector introduced with Hi-8 and S-VHS. This connector separates the luma ("Y") signal from the chroma ("C") signals, providing a quality boost for transfers from the BVU-800 to equipment that also has dub connectors. Usually that is another U-matic tape machine, although some TBCs have a U-matic dub input. It's important to note that while early JVC S-VHS machines used the same connector for the S-Video signal, these two signals are not the same.

The BVU-800 has XLR audio connectors. The audio output is +4 db, and will be compatible with broadcast recording machines.

Transferring U-matic tapes is usually straightforward, but Problems can occur. A very early U-matic tape that we were trying to transfer played perfectly for five minutes of the 30 minute program, and then began to rewind. After trying a test tape to verify that the tape machine was working correctly, we looked at the tape at that spot. You can access the tape on a cassette with a little trap door button somewhere near the front of the tape. I was worried that the tape would be crinkled or twisted at that spot, and not proceed along the tape path. What I found at that spot was clear tape; the magnetic material had stripped away from the tape for about a quarter inch.

What we were experiencing was the successful functioning of the auto rewind feature on the tape machines. A U-matic tape is normally clear for the last few inches, where the tapes is attached to the cassette reels. The U-matic tape machine has a sensor which identifies the end of the tape; it consists of an infrared light on one side of the tape path and a mirror on the other. When the infrared "sees" the mirror, it knows it is at the end of the tape. In our case, the transparent area on the tape was sensed as the end of the tape.

To play the entire program back we placed a piece of opaque tape over the infrared light sensor. As long as the tape was in place, the light would never "see" the mirror. We removed the top of the machine in order to carefully monitor the tape progress during playback, because we had disabled the end-of-tape function. With this function disabled, the machine could pull the tape right off the reel at the end of the tape.

Time code signal on U-matic tapes is a variable. Not all U-matic tape is time coded. If time code was recorded in the field, it was recorded on the address track, a digital track that shares tape space with the video signal. If the tape was post-coded, the time code was usually on one of the audio tracks, typically track 2. Eventually, Sony marketed a modification to BVU models that added a switch - audio 1, audio 2, or address track. With this, the time code on the tape can be read regardless of where it was recorded.

If time code is being transferred with other signals, it should go through a time code reshaper. This device guarantees that time code will have the proper waveform and thus, will be read correctly. At BAVC, the time code generators in the facilities control room which houses the remastering center are used to regenerate and reshape time code from U-matic tapes. This may not be as much of an issue as time passes.

• The issue of recording formats
• Preferred preservation formats
• Formats not recommended

The issue of recording formats

Starting with the first tape BAVC transferred, the choice of recording formats has been controversial. For example, BAVC learned that the Minnesota Historical Society, with advice from technicians at 3M, chose S-VHS as the recording format. The stock is inexpensive, the players are plentiful, and the format is stable. The S-Video standard allows for better signal integrity relative to a composite transfer.

Since the center opened, debates have continued about the best preservation format. Granted, it would be difficult to tout S-VHS as an archival format equal to Betacam SP or Digital Betacam. However, the preferred format for a technician in the independent media field may be different from those recommended by an archivist or a conservator.

The technician's question, first and foremost, is often: "Do you want to see your tape again?" A technician is concerned about the shelf life of a tape format and its ability to reproduce the image and sound of the original,. Many of BAVC's clients do not have outside funding for the project , and some are not interested in issues of conservation. At BAVC, our focus was on preserving the original tape and accepting the reality that there is no ideal format. BAVC explains options to the client, Who then makes a decision about formats.

In my opinion there are recording formats that should be avoided and others that are best for transferring obsolete tape formats.

Preferred preservation formats

The preferred formats to transfer to are SVHS, Betacam SP, Digital Betacam and D1.

? S-VHS - A composite analog format that is cheap, easy to find and provides reasonable quality. A valid choice for a budget transfer.

? Betacam SP - A component analog format that has become the standard in broadcast production. The video signal is actually 3 discrete signals, and these signals are even recorded separately on the tape. While Betacam SP offers the best recording quality in an analog format, it has the reputation of having more dropout than U-matic and one inch. Also, the less expensive UVW Betacam SP tape machines are much less robust than the broadcast models, and have more problems.

? Digital Betacam - The preferred recording format at BAVC is a controversial choice. Digital Betacam offers 4:2:2 component recording and is a clear market leader in the video production community. But Digital Betacam is also digital recording and has 2:1 DCT compression. While there are many arguments to "stay analog" in remastering, the reality is video production has not been all-analog in twenty years, since digital time base correctors began to be widely used. The TBC, an essential tool for recording a viewable image from 1/2" open reel, is a digital box that converts analog signals to digital and digital signals to analog.. If you use a TBC to transfer, you've already moved from analog to digital. The issue of compression is much stickier; the question really is whether DCT compression, as it is implemented on Digital Betacam, is transparent enough for the purposes of video remastering. Given the market dominance of Digital Betacam, the viewable quality of the image and its cost-efficiency, the DCT compression of Digital Betacam seems acceptable, especially considering the relative low technical quality of the original formats being transferred.

? D1 - An uncompressed digital component format. BAVC was not able to justify the expense.

Formats not recommended

In my opinion, there is a high risk when transferring tapes from obsolete formats to 8mm/Hi-8, MII, DCT, DV/Digital 8, Betacam SX or DVD.

? 8mm/ Hi-8 - These formats employ tiny tapes; engineers hate to work on such small scale machines. Hi-8 offers the same image quality as S-VHS but more dropout. It is a format that has been superseded by the small digital formats; however, there are still plenty of tape machines out there. In the future, 8mm/Hi-8 will pose challenges for preservation.

? MII - A Panasonic format that is equal Betacam SP's equal in everyway except popularity. MII tape machines are hard to find.

? DCT - Ampex's digital component format. Ahead of its time. Long gone.

? DV/Digital 8 - Both formats are designed to be cost effective digital formats. Compression is reasonable for field acquisition (5:1 DCT), formats are 4:1:1 component, with 2 chroma (1 B-Y signal, 1 R-Y) signals for 4 Y (luma) signals. Tapes and tape paths are tiny, making the machines difficult to work on and probably less reliable than the larger formats. DVCPRO 50 offers better quality but is stillvery small.

? Betacam SX - A compressed digital 4:2:0 component format that is strictly for field acquisition.

? DVD - This digital format is designed for distribution, not for remastering.

Transferring tapes to one inch, U-matic, D3/D5, D2 or Digital S is not recommended, although the risk is somewhat less than transfers to the formats listed above.
? One inch and 3/4" U-matic - Should be considered an obsolete formats for remastering. Reliable technicians, machines and parts are increasingly difficult to locate.

? D3/D5 - Panasonic's answer to Sony's D2 and D1. Great quality, But machines are difficult to locate.

? D2 - An uncompressed composite digital format that has been superseded in the marketplace by a compressed component format, Digital Betacam.

? Digital S - A digital format with the form factor of VHS and the specs of Digital Betacam. An attractive idea with a small market share.

• Devices for monitoring and switching
• Time base correctors and the Sony BVT-810
• Waveforms and vectorscopes
• Signal Switcher and Video Distribution Amplifier
• Monitors and cross-pulse
• Overall configuration

Devices for monitoring and switching

The transfer process, at its simplest, requires:

• a source tape player
• a recorder
• cables between the two

Ideally, you will also have devices for monitoring, generating bars and tone, maintaining a stable signal and doing audio or video processing. These devices are discussed in later sections.

The remastering process requires additional equipment to give the operator the opportunity to monitor and to transfer the tape efficiently. At BAVC, this equipment includes:

• time base corrector (TBC)
• a six input, one output (6X1) video switcher
• a one input, six output (1X6) video distribution amplifier (VDA)
• a combine waveform and vectorscope monitor
• a color monitor with cross-pulse controls and at least 2 inputs.

BAVC also has a color bars generator, a device that outputs a standard bars signal, and a tone generator. These devices are used as sources for the bars and tone recorded on the beginning of a transferred tape, to provide reference signals for color, black, and audio levels.

Bars are a video signal recorded at the head of a tape. At BAVC the signal is typically recorded for 1 minute simultaneously with an audio tone. The colors in the bars are used to adjust a TBC to the incoming tape's signal. Because of this, the video signal on the rest of the recording should have a close correspondence, in hue, saturation, brightness and black level, to the bars reference signal at the beginning.

Tone is recorded along with the bars and is 1 kiloHertz. Because the audio vu meters on the recording machine are adjusted to the tone, the audio on the rest of the program should correspond with the reference tone at the beginning.

Time base correctors and the Sony BVT-810

A videotape machine mechanically scans the tape using a rotating tape head. This function introduces errors in the signal, known as time base errors. These are recorded on the tape and are prevalent in small formats like 1/2" open reel and U-matic.

To correct these errors, a digital device called a time base corrector or TBC was developed in the mid-1970s. The output of a videotape machine is sent to the input of the TBC. The TBC writes the unstable signal into a memory buffer and reads it out, stabilizing it with its own crystal-stable clock. It is like capturing a frame of video, or a portion of a frame, stabilizing it and instantaneously sending that frame to the video out. The TBC then does it all over and over again faster, than 30 frames per second. Older TBC would handle 16 lines at a time. Today most external TBCs are also frame buffers, and are known as full frame TBCs. Because these devices have a frame buffer built in, manufacturers usually add image processing features like freeze frame and strobe.

While correcting time base errors is the primary purpose of TBCs, they also perform another vital function. TBCs provide controls for changing the brightness, contrast, hue and color saturation of a video signal. On the control panel, these functions are usually identified as Luma (brightness), Setup (contrast), Hue (color) and Chroma (saturation).

BAVC uses a Sony BVT-810, a 16 line TBC originally used with BVU-800 U-matic tape machines. A TBC that is not full frame requires that the source tape machine be fed an "Advanced Sync" signal from the TBC into a "sync in" of the tape machine. The BVU-800 U-matic has a "sync in" BNC connector. The "video in" of the AV-8650' doubles as a "Sync in." The CV-2100 does not have a "Sync in" and so it cannot be directly used with the BVT-810.

The BVT 810 is an older model TBC. This offers an advantage because full frame TBCs have an inherent flaw when processing weak and unstable video signals. If the full frame TBC cannot process the video correctly, it strobes the image. Since the BVT-810 is only processing 16 lines at a time, it is more likely to be able to address image problems which a full frame TBC cannot.

The DPS TBC is a full frame TBC that is designed to either be mounted in an ISA expansion slot of a PC or Amiga and controlled through software or in a DPS control box with external control switches and buttons.

BAVC chose the DPS TBC because of its functions and price. Early attempts by BAVC to use a much more expensive TBC (Prime Image 600+) with 1/2" open reel had been unsuccessful. The DPS TBC has worked well as an alternative to the BVT-810.

Because it is a full frame TBC, the DPS requires only a video input connection to the source video tape machine. Unlike the BVT-810, this TBC will work correctly with a video signal coming from the CV-2100.

BAVC's DPS TBC is mounted in a DPS box along with a DPS Vscope, a card that provides vectorscope and waveform monitoring.

Waveforms and vectorscopes

A waveform monitor and vectorscope are essential tools for any video system which includes a TBC. To understand the purpose of these tools, we must think of them in relationship to a video monitor. In a system like BAVC's remastering center, the waveform monitor and the vectorscope are connected in line with the color monitor. These three displays, - waveform monitor, vectorscope and color monitor - are looking at exactly the same video. Each is designed to visually display information about the video signal. Each must be properly calibrated.

The typical use for the waveform monitor is to indicate the brightness and darkness of the video image. It measures the "original" video signal, the monochrome signal that we identify with Ernie Kovacs and Howdy Doody. The waveform monitor has horizontal lines etched on its screen, each line representing IRE units named after Institute of Radio Engineers.

  Waveform monitor display
 
 

A legal broadcast video signal ranges from -40 IRE at the bottom of the waveform monitor screen to 100 IRE at the top. The only part of this range that represents visible video is from 7.5 IRE to 100 IRE. One third of the useable video spectrum is not visible, and has been set aside for keeping the video image in sync.

The waveform monitor in BAVC's center is used to keep the video signal withinthe acceptable legal broadcast limits.

With the top of sync at 0 IRE, the bottom of sync must be at -40 IRE, black must be at 7.5 IRE and the top of the video signal must never go above 100 IRE.

How do you adjust these levels? Remember the waveform monitor is just a monitor, like the color monitor. If you make adjustments to the waveform monitor you are not making any changes in the signal itself, only in the display on the monitor., If it needs adjustment, the signal will be adjusted at the TBC.

To adjust the black levels of the signal to 7.5 IRE, you will adjust the setup (also known as the pedestal or black level) on the TBC. To adjust brightness to 100 IRE, you will change the setting for luma on the TBC.

This is a very basic use for the waveform monitor, but perfect for transferring 1/2" open reel and U-matic. Waveform monitors are also used to "time" the horizontal sync of older composite online editing suites, verify time code phase and measure parts of the video signal with engineering names like the breezeway, the back porch, and the front porch.

Sherry Miller Hocking's "Principles of Image Processing - Sync" on the Video History Site  gives a detailed description of the sync signal and its component parts.

The vectorscope is optimized to display the color information of the video signal. Six boxes with crosshairs are located at specific points on its display screen. When a color bars signal is passed to the vectorscope and the signal is calibrated and oriented properly, six points in the video signal will land on each of the crosshairs. On the screen, next to the box/crosshairs are labels R, Mg, B, Cy, G, Yl. These mark the color associated with each box/crosshairs: Red, Magenta, Blue, Cyan, Green and Yellow.

  Vectorscope display
 

Like the waveform monitor, the vectorscope is only for monitoring. Changing the chroma setting on a TBC which then sends a signal to the vectorscope will cause the signal on screen to stretch out towards the edges of the display. Adjusting the hue on the TBC causes the video signal on the vectorscope to spin. Red travels towards Magenta or Yellow. The colors change.

Traditional waveform monitors and vectorscopes come in separate instrument cases, have green displays and resemble oscilloscopes. BAVC's center uses a waveform monitor/vectorscope called the Vscope by DPS. This device is an expansion card that will fit in a PC with an ISA slot or in an Amiga. It mounts in the same DPS expansion box as the DPS TBC. The Vscope has a BNC monitor output that can be sent to a color monitor. On the color monitor, the Vscope display can be toggled on and off.

One good feature of the Vscope is that its levels cannot be adjusted. All too often not-so-clever fingers adjust the knobs on monitoring devices, taking them out of calibration. If there is a discrepancy between the video signal as viewed on the color monitor and the one that is shown on the waveform monitor and vectorscope, the waveform monitor and vectorscope are almost always right. The discrepancy should always be verified with a reliable color bars signal.

Signal Switcher and Video Distribution Amplifier

The video/audio switcher in BAVC's remastering center is a simple routing device with six buttons on the front. On the back of the switcher is a bank of connectors corresponding to each button, with one video and two audio inputs. Each of the tape machines' video and audio outputs are connected to one of the input banks, and the selected buttons sends the inputs to the one output of the switcher.

The purpose of a video switcher is to give the technician an efficient means Of switching among a number of devices; at BAVC we use the switcher to select among a number of playback decks. Without a switcher the technician would need to re-cable each deck every time the configuration changed. Initially when a 1/2" open reel tape is played back, the technician does not know whether it is "skip field" or EIAJ. Also, tapes play slightly differently on the two different EIAJ tape machines. As the tape is mounted on a tape machine, the tech need only select the switcher button corresponding to that machine to send the video signal to the TBCs and the monitor. When it comes time to do the transfer, the audio is patched to the audio input of the recording machine.

A video distribution amplifier multiplies the output of the switcher. This VDA takes one input (the switcher's output) and amplifies it and sends it to six outputs. These outputs are connected to the two TBCs and to the B Input of the monitor. One output on the VDA is unused. Now the signal of each tape machine can be viewed as it passes through the BVT-810, through the DPS TBC IV, and as it goes directly to the monitor. The technician has the opportunity to choose the best process for the video signal before doing the transfer.

BAVC's video/audio switcher and video distribution amplifier are made by Sigma. The two devices can be mounted in a Sigma rackmount tray, and they both take up only one rack space.

Monitors and cross-pulse

For almost everyone, the color monitor isthe portal to the images captured on tape. NTSC video is notoriously unstable. The standard NTSC is popularly known by video technicians as "Never The Same Color" As the messenger of the signal, the color monitor can offer technicians a wealth of information about the video signal as it plays back. if the monitors are maintained and correctly calibrated.

In a remastering setup, the color monitor should have at least 2 video inputs. One will receive the signal that is being processed through the video/audio switcher, VDA, TBCs and Vscope. The other signal should come directly out of the VDA, so that there is no TBC correction to tape signal.

The color monitor should have a cross pulse switch. This switch takes the video signal and re-centers it in the corner. The image is brightened and cut in two by the horizontal and vertical sync bars. In this mode the image is unrecognizable.

By viewing with the cross pulse switch activated you can analyze that large part of the video signal that is used for synchronization.

What will you see? If you are looking at a signal that is passing through a TBC, you should see clear, straight black bars in the center, one horizontal, one vertical. If there is a sync problem between the TBC and the originating video tape machine, vertical rolls may be very subtle. Viewing the signal in cross pulse will reveal the problem. Because the BAVC system allows switching between the same tape signal passing through different TBCs, the cross pulse view of the output will give you the information which will help you choose one TBC over another for the transfer.

The cross pulse switch is useful when viewing a signal on the second video input, as a signal that is not being corrected by a TBC. Without a TBC you will be able to see the skew errors, tracking problems, head switches. Essentially, you will see all the problems that are part of the sync on that tape. Once you know the problems, you will be able to better judge the course to take with the tape. Watching a tape without going through a TBC also gives you an early warning if the TBC is causing strobing or other problems associated with processing old tapes through TBCs.

The playback tape machine, the recorder, the video/audio switcher, the VDA, the TBC, the waveform monitor/vectorscope and the color monitor are all connected in a way that provides the technician with the most efficient method of transferring from the playback tape machine to the recorder.

Overall configuration

The following is the logic behind BAVC's setup:
 

• Tape machines must be centrally located so tapes can be easily switched from one playback machine to another. If you put a tape on an AV-8650 and after some playback you realize it is a "skip-field" tape, the CV-2100 must be close at hand and ready to playback the tape. If playback of an EIAJ tape is a problem on AV-8650 switching to a second AV-8650 may improve playback due to tape interchange problems since all AV-8650s seem to playback a little differently, or because of differences in maintenance of the two AV-8650s.
• Viewing the signals through the different signal paths must be accomplished with a minimum of re-patching. You should be able to troubleshoot the playback of a tape by switching playback tape machines or TBCs, rather than re-cabling.

 
 

With these two design requirements, BAVC's remastering center is connected in this way:

1. Playback tape machines

• First in the signal flow are the 2 AV-8650s, the CV-2100 and the BVU-800.

2. Audio/video switcher

• Each playback machine is connected to one of the inputs of the A/V switcher.
• The video output of the A/V switcher is connected to the input of a Video Distribution Amplifier (VDA)
• The audio output of the A/V switcher is connected to 2 patchpoints on BAVC's control room audio patchbay

3. Video output of VDA

• The video output of the VDA is sent to each TBC, the full frame DPS TBC IV and the 16 line BVT-810.
• An uncorrected video signal (does not go through a TBC) from the VDA is sent directly to color monitor input B. If there is any question about the affect a TBC is having on a signal the operator can press a button on the color monitor to view the uncorrected signal as a reference.

4. Outputs of the TBCs

• The outputs of the two TBCs are connected to patchpoints on BAVC's control room video patchbay.

5. Video patchbay

• The selected video signal is patched to the VDA.

6. VDA and audio to recorder

• The video signal from the VDA and the audio signals are patched to the record tape machine.

7. VDA to waveform monitor/vectorscope

• The video signal from the VDA is patched to the remastering center's waveform monitor/vectorscope.

8. Color monitor A input

•  The video monitor output from the waveform monitor/vectorscope is sent to the A input of the color monitor. From the control panel of the waveform monitor/vectorscope, the video sent to the A input (waveform monitor, vectorscope, color picture, mix) can be selected.

9. Advanced sync from BVT810

• The advanced sync output of the BVT-810 TBC is sent to the two AV-8650s video inputs and to the BVU-800's "sync in" using BNC barrel connectors.

Appendix 12.2 shows block diagram of the signal flow in the system.

• Maintenance
• Cleaning on open reel decks: heads, tape path and slip rings

Maintenance

Anyone who has worked in a video facility knows that one of the biggest maintenance issues is keeping the cables going to the right place. With this design the cabling for the different parts of the system will only need to be disconnected for maintenance on equipment.

Once you minimize the need for re-cabling, the next concern is keeping the playback tape machines workingaccording to the manufacturer's specifications. This is particularly difficult with 1/2" open reel, because replacements for many of the key parts are no longer manufactured. The alternatives are to take good care of the equipment and, if possible, acquire machines which can be cannibalized for parts. Many of the basic parts like rollers and drive belts on 1/2" open reels are still available because they are also used by reel to reel audiotape machines.

BAVC has relied on a book in its library called The Video Guide, by Charles Bensinger (Video-Info Productions, 1979). The Bensinger guide has been an essential reference for working with 1/2" open reel. My understanding of how to clean AV-8650 heads comes from the guide.

Cleaning on open reel decks: heads, tape path and slip rings

To clean the video heads of an AV-8650 you will need lint free cleaning cloth rated for clean-rooms and denatured alcohol. The quality of the cloth and alcohol is much higher than what you can buy at drugstores.

These items are often available at the larger electronics stores.

The power to the machine must be off to clean video heads on the AV 8650. Switch the function lever to REW or FF. If you rotate the supply reel spindle you should see the video heads spin inside the video head drum.

Douse the cloth liberally with alcohol and place it firmly against the video head drum in the heads path. Rotate the supply spindle and let the video head contact the alcohol/cloth as it spins four or five times.
Do not move the cloth as this happens, and apply minimal pressure against the cloth to hold it in the head's path.

 
 

The CV-2100 does not spin the heads like the AV-8650. In the case of the CV-2100, you must take off the top of the video head drum; the top is held with two small screws. Manually spin the heads as you hold the alcohol/cloth in place next to the video head drum. Continue this process until you no longer accumulate debris.

The stationary heads, including the audio and control track heads, don't require this much care. They can be rubbed with the alcohol/cloth with some pressure, almost as if you are buffing them.

Carefully inspect the path the tape travels to make sure there is no debris left in the tape path. There are grooves along the bottom of the tape path to guide the tape. If necessary run a toothpick along these grooves to make sure any buildup is removed.

The pinch roller is a rubber wheel in the tape path that grips the tape and helps to pull it along at a steady rate. If this roller gets shiny it will no longer provided the needed traction for the tape path. In this case, the tape could even slip out of the direct tape path and cause playback problems or tape damage.

Inside the video head drum is a spindle on which the video heads rotate.. At the top if this spindle are a number of wires making contact with grooves on the spindle. They are called the slip rings. They carry the video signal to the electronics. After some use the grooves in the spindle can accumulate debris and cause black dropouts in the video signal. To clean these slip rings you must remove the video head drum cover, turn the tape machine on and dowse a swab or clean cloth in alcohol. Put the machine in stand-by and so the video heads turn. Apply the swab or cloth to the slip rings, being sure to access the recesses of the grooves. Continue this process until you no longer accumulate debris.

At first, documentation was simple. When BAVC received tapes from a client the tapes were inventoried and sent to our off-site cleaning technician. When the tapes were returned, they were checked off against the inventory list. After remastering, the original 1/2" open reel tape and the new copy were rubber-banded together so they would not get separated. A label was created for the copy that included title, artist, running time, format of original and client name.

As new personnel began to work in the remastering center, and as more jobs came in, we needed to have better documentation for business purposes. If remastering work was done on the weekend or in the evening, the day staff needed to know the status of a job to answer any questions the client might have.

At the same time, we became aware that many of our clients were not the originalcreators of the tapes, many were not familiar with video production, particularly work made using now obsolete production tools and practices, and many had never viewed the tapes they were remastering. In fact, often the client had no idea what was on the tapes.

Also, we learned that when clients viewed the finished tape, they were surprised and concerned by technical artifacts that BAVC technicians took for granted. ( These included dropout or editing glitches. Clients were occasionally dissatisfied with artifacts on the remastered tapes which were intentionally created by the artist or the result of the technology of the times - artifacts not related to the remastering work done by BAVC. The most common concerns were:

• No color

 

• No sound

 

• No titles or credits

 

• Several seconds of video noise between program segments

 

• Herringbone patterns in video (such as created by shooting video off of a monitor)

 

BAVC began to anticipate these concerns; before a transfer took place, we prepared the clients for what they might see. Using a form called a "Preservation Dub Watch," technicians began to document these factors and other "deviations" from what one might expect when viewing a contemporary tape that is playing back properly. Obviously these notations were subjective, but we tried to be as detailed as possible. , These observations sometimes revealed equipment problems, as opposed to tape issues, that could berepaired.

The dub watch form is still in use at BAVC. While many technical issues are now routine, the form serves an important function and is a great way for technical staff to communicate about specific jobs from one shift to the next.

The form also provides the client with a snapshot of the transfer process. As mentioned above, the tapes that BAVC receives are often unlabelled and the contents are faintly remembered or unknown. The dub watch form and proper tape labeling of the copy provide valuable information to the client. If ownership of the tape changes in the future, this information will also be valuable to the new caretaker.

BAVC's current preservation staff recommends the monograph Playback: A Preservation Primer for Video (BAVC, 1998) for further information on documentation.

See Appendix 12.3 for the Preservation Dub Watch Sheet

• Notes on the economics
• Looking to the future

Notes on the economics

From the start, the remastering center was attractive to funders but presented a knotty business challenge. Remastering is like videotape dubbing: video and audio signals on a source tape are transferred to a new tape. However, remastering is a much riskier venture, because correct playback of the tape is not guaranteed and it often requires extra work. Yet BAVC remastering services must not be priced beyond the market of media artists and nonprofit organizations.

A remastering facility presents a number of concerns relating to the allocation of staff time and fundraising and budgeting.

Transferring a 1/2" open reel tape may take from 2 to 3 hours, if all goes well. The tape must be cleaned (typically at least 5 passes on the cleaning machine), taking about 40-50 minutes. The new master tape is packed (fast forwarded and rewound); color bars, tone and slate are recorded at the head of the tape, and the system is patched for the transfer (about 20-30 minutes). The 1/2" open reel tape is mounted on the playback machine and either played back to check playback audio and video levels (20-30 minutes). Finally, the 1/2" open reel video is recorded onto the new master (40-80 minutes). Cleaning the tape paths for each transfer (10 minutes).

The length of time required can easily increase if the video head clogs on playback, or the tape needs more cleaning, or any number of other tape problems arise during the transfer.

This work is not suitable for interns. A well-trained technician must perform all of these tasks in addition to the task of documentation.

Clients want to know that their tapes are being handled by experienced technicians. Yet, BAVC wanted to keep the costs of transfer down, and insure that the fees also cover other costs. One of BAVC's frustrations is to maintain qualified technicians willing to accept the pay level the center could afford. In the early years, technicians were paid $15 per hour.

What about the costs of maintenance? I always set aside 20% of income for maintenance costs.

Overhead costs include the consulting work done with clients before and after transfers. An lesson we soon learned at BAVC is that our clients may be completely surprised by what is on their tapes. I visited the Minnesota Historical Society after their project was completed to review tapes they had questions about. One video had a herringbone pattern appearing in the picture. We discovered the tape was a copy of the original tape, produced by videotaping a television monitor. Staff of the Historical Society were also surprised by the crudeness of some of the video production techniques. Some of the programs were separated from each other by a few seconds of video noise. I clarified that this was not a result of the transfer, but the way the production was originally recorded on the videotape.

While BAVC has refined its techniques for interviewing clients before and after the remastering process, the managing and delivering of a remastering project is still very time-consuming.

BAVC must also take into account the overhead for every project in order to keep the organization running. In trying to keep costs as low as possible for our low-budget clients, I often regretted having to include the cost of overhead - costs such as equipment, rent, and utilities. The reality is that these costs are necessary to keeping the remastering facility open.

The efforts to make money, keep staff, and maintain quality were wearing. BAVC was very fortunate that Heather Weaver and John Selsey had the interest and ability to sustain the facility as my drive to keep the center functioning was ebbing..

While as a business remastering is a struggle, the services have been a key ingredient in BAVC's successful fundraising for preservation. Along with funding for physical remastering, BAVC was awarded funding to hold a conference of conservators, "Playback 96: Video Roundtable" to address video preservation and its importance to art conservators. "Playback" and BAVC's other preservation-related projects also gave the remastering program credibility and, it was hoped, a broader client base. Also, in the same time period as "Playback", BAVC partnered with the National Initiative to Preserve American Dance (NIPAD) to train dance companies to use video to document dance. All of these related activities strengthen BAVC's ability to secure funding from sources such as the NEA Heritage and Preservation Program.

While video remastering has had a net positive effect on BAVC and the media arts field, there is a great need for BAVC and others to improve remastering techniques. In the following section I include a wish list for projects that I along with other BAVC technicians - current and past - would like to see developed. Also, it seems clear that creating a plan to expand the number of remastering centers is an important next step to sustain the work.

Looking to the future

From a technician's point of view, there are a number of steps which could improve the process of transferring obsolete tape formats.

There must be more attention and funding devoted to video remastering. More support would increase the number of technicians addressing the issue and broaden the technical knowledge-base. In the nonprofit media arts field, remastering has not grown beyond BAVC's model. Even within BAVC, only a tiny pool of talented technicians has maintained the program. New BAVC technicians tend to forgo learning the remastering process, concentrating instead on learning new technologies, such as nonlinear editing systems.

A larger pool of technicians and the funding for their research will increase the quality and frequency of debate and innovation in video remastering. If engineers, conservators and researchers from related disciplines can join technicians in this work, the dialog willbecome more productive. Currently BAVC works with only one engineer who has the expertise and interest to maintain obsolete cleaning machines and video decks, but his relationship is as an independent contractor, not a collaborator interested in advancing the practice of remastering.

In, particular, there is a need for research and experimentation with the preparation and cleaning process. The methods used by BAVC have not changed since BAVC began remastering.

Specifically, BAVC technicians and colleagues in the field would like to explore:

• Research other preparation techniques such as tape baking or tape washing. Baking is especially interesting, because engineers at 3M and Ampex have already performed this process. While they claim that it may be destructive, allowing for only one transfer, it would be worth further study.
• Develop a combination cleaning/playback machine (replacing record heads with cleaning modules). By eliminating the cleaning machine, essentially integrating it into the playback tape path, it could: 1) make the remastering process more efficient; 2) reduce the cost of setting up remastering facilities; and 3) reduce the number of machines to learn to operate; and 4) reduce maintenance.
• Develop a re-designed 1/2" open reel playback machine, including a kinder tape path with a vacuum chamber, and highly adjustable tracking and skew. Creating a new machine to address this issue is the more expensive approach but perhaps the wisest. Currently, technicians are using 30-year-old equipment to remaster tapes. We are not taking advantage of the innovations in tape handling, and we are not taking into consideration the special needs of a remastering project - where tapes have been recorded on machines that may vary widely in terms of maintenance and calibration.
• Develop a process for transferring the signal from a 1/2" open reel tape magnetically to a new tape. This technology is currently used in high-end VHS tape duplication. A master videotape is run though a machine where it makes physical contact with a new tape and transfers all signals magnetically, without a tape path or video head. If this process could be developed for 1/2" open reel tapes, we could save the wear and tear on the original. The new copy could then be run through the tape path, also saving some wear and tear on playback machines.
• Explore transfer to an uncompressed nonlinear workstation such as the Avid Symphony. The material would be saved in D1 quality as an intermediary, with possible "touch up" done on marginal frames. This process would maintain the quality of the original but give the facility time to review and approve of the transfer before it is transferred to tape.
• Research data backup as an adjunct to remastering. Is there a backup medium and file format that has a long-term future and can hold the amount of data contained in a video tape? Is this format DLT, or the D1 data tape developed for storing media? This process could store signals long term while further research is done to develop or agree upon a preservation format for video.
• Collaborate on such projects as the WGBH's Universal Preservation Format Initiative. If there are better funded projects that are addressing the basic needs of video preservation, the media arts field should be aware of them and, perhaps, participate.

• Tape Cleaning Equipment Manufacturers
• Block Diagrams of BAVC's Remastering Facility
• Dub Sheet

Tape Cleaning Equipment Manufacturers

Data Devices International
advertises a line of cleaners

The Bow Industries
features a section by Dale Whysong on the mechanical removal of particles adhered to a magnetic tape surface; they also advertise tape cleaning services

Recortec
408-928-1480, fax 408-729-3661 or email [email protected]

RTI Group
makes cleaners for everything from VHS to DVCAM tapes. RTI can be reached at 847-677-3000, 800-323-7520 or 818-838-0480; [email protected].

 

Block Diagrams of BAVC's Remastering Facility
 

 
 

Dub Sheet