Interview with Ramon Coelho (NIMk)

Nederlands Instituut voor Mediakunst, Amsterdam, April 23, 2009


Ramon Coelho works at the Nederlands Instituut voor Mediakunst–Montevideo/Time-Based Arts (NIMk) in Amsterdam, where he is responsible for postproduction and conservation.

In connection with a digitisation assignment that is part of the research project entitled ‘Preservation and Access to Multimedia Data in Flanders (BOM-Vl), PACKED coordinator Rony Vissers talked to him about the digitisation and conservation of video art and documents.


Since it was founded in 1978, the NIMk, in addition to holding exhibitions, has accumulated a sizeable collection of video and media art to which new works are constantly being added. The institute also produces, distributes and presents works of media art.

From 1992 the NIMk also developed into a centre of expertise on the conservation of media art, in which field it generates models and theories. It also restores and conserves private and other video collections and administers the Netherlands’ video art storage centre. Because of its long history and the extensive experience and know-how it has built up, the NIMk has an important role both in and outside the Netherlands. It is acknowledged worldwide as one of the main experts on the conservation of media art.

As part of BOM-Vl, the NIMk was asked to digitise a varied range of analogue video tapes from collections held by cultural institutions in Flanders. BOM-Vl is an initiative of the Flemish Ministry of Economy, Enterprise, Science and Innovation, with the support of the Ministry of the Flemish Community. BOM-Vl is intended to provide solutions for the judicious long-term preservation of the audiovisual heritage in Flanders, as well as making it accessible and available for exchange. The project ran from 1 January 2008 to 30 June 2009 and was implemented by a consortium involving partners from both the cultural sector and the audiovisual media sector.1

Since the bulk of the audiovisual heritage in the Flemish cultural sector is still based on analogue media, at the instigation of the Flemish Ministry of Economy, Enterprise, Science and Innovation it was decided to make funds available for the digitisation of a selection of analogue works as part of BOM-Vl. The Interdisciplinary Institute for Broadband Technology (IBBT) put out a request for tenders.2

After a comparison of both the tenders and the results of several tests, the task of digitising these video works was entrusted to the NIMk. Several cultural institutions were requested to make a selection from their collections: the AMSAB Institute of Social History,3 M HKA,4 SMAK5 and the Antwerp Municipal Archives.67

The budget for this digitisation was administered by the IBBT. The process of delivery, digitisation and ingest was followed up by the BAM (Institute for Visual, Audiovisual and Media Art),8 with the assistance of PACKED (Platform for the Archiving and Conservation of the Audiovisual Arts) and FARO (Flemish Centre for the Cultural Heritage).9 The ingest of the BOM-Vl Demonstrator itself was supported by the IBBT/ilab.

At the NIMk, the digitisation itself was carried out by Mario Vrugt (from ¾” U-matic, VHS and 1” tapes), Jata Haan (1” tapes) and Ramon Coelho (project management and monitoring).


 Digitisation of 3/4" U-matic tapes (Ramon Coelho), Nederlands Instituut voor Mediakunst, courtesy: NIMk


PACKED: What is your personal background? Did you have any video training?

Ramon Coelho: Yes, I did once take a course in video, but only later. Actually I was brought up on the practical side of it. My father, René Coelho, founded the Montevideo video gallery in 1978. I was 16 or 17 at the time, and interested in the technical side of video. I was already involved in electronics and made electronic musical instruments myself. But I only turned to the technical aspect of video several years later, in the eighties. That’s when I took a course in video editing, among other things. So most of my knowledge has been gained through practical experience. It covers the whole range of video: editing, production assistance to video artists, renting audiovisual equipment to artists and so on.


PACKED: And your experience with conservation?

Ramon Coelho: In the nineties it became clear that something had to be done in the Netherlands to safeguard the long-term preservation of older video works. It was my father who rang the alarm bell. Something had to be done urgently, because a number of early tapes of video art could no longer be played.

This resulted in the first round of conservation of videos from Dutch visual art collections. At that time, there was a ‘Deltaplan voor Cultuurbehoud’ in the Netherlands, and our first round of video art conservation was made part of that and thereby received financial support.

Eight collections took part in the first round of conservation. They also made their own financial contribution. A method was then very quickly devised to safeguard the videos in these collections. We developed it on the basis not only of our own work experience, but also on consultation with video technicians (some from television broadcasters) and equipment suppliers.

In December 1992 we started copying the most important tapes that were in danger of decay to the more stable Betacam SP format.10

Because there was some panic, everything was copied, without any selection. We did not wonder what we should copy and what not. At the time, the video documents were also copied in addition to the works of art themselves.


PACKED: Were you involved in that first conservation work from the beginning?

Ramon Coelho: Yes, I carried out the project with a colleague. It amounted to 1200 to 1300 hours of video. We worked on it two and a half days a week for two years. It was very intensive; you couldn’t keep it up if you were doing it full-time. So I did it part-time with a colleague.


PACKED: So to a great extent the knowledge and skills you needed for conservation work developed out of your experience as a video editor?

Ramon Coelho: Yes, that was the foundation for the basic experience of our first conservation work, as well as my experience setting up exhibitions. I did that a lot. It also involved a lot of troubleshooting with equipment. At that time, players for ¾” U-matic were still important for exhibitions. I had to find a solution not only when projections went wrong in exhibitions, but also for tapes and players when the heads were dirty or the signal connections were wrong. This experience grew over time and evolved along with the equipment.


PACKED: Can you also tell us something about the second series of conservation work?

Ramon Coelho: The first stage of conservation consisted of copying works on earlier tape formats such as ¾” U-matic and ½” open reel11 to Betacam SP. In the second stage, these analogue Betacam SP tapes were copied to digital Betacam tapes. We started this digitisation in 2001. I took an active part in that too. To avoid our choices being made purely on the basis of our own findings, we asked for advice from external experts for that second stage too.

The need also arose for an independent platform, and so on the initiative of the institutions involved the project was placed under the wing of the Foundation for the Preservation of Modern Art.12 This second stage of conservation, which came to an end in February 2003, also included works of video art from several Dutch museums and institutions.13


PACKED: So in the second stage you did not start out from the original masters, but from the Betacam SP conservation masters that resulted from the first stage of conservation?

Ramon Coelho: That’s right, but we did not opt for that out of laziness or to save money. In the first stage of conservation we copied the tapes in the best possible way, with the best connections, using cleaning machines for ¾” U-matic and ½” open reel, and so on. This cost a lot of blood, sweat and tears. By the time of the second stage, the tapes were again ten years older, and players had not improved either. On that basis we decided we did not need to repeat the process.


PACKED: So at present you store the conservation masters on digital Betacam. But what format is used to view the tapes?

Ramon Coelho: MPEG-2. The files are on a file server and on DVDs that are stored in a cupboard.


PACKED: In the meantime, it is already six years since the second stage of conservation. Have you since then been preparing for the move to tapeless storage?

Ramon Coelho: Yes. At the end of 2008 our Playout Project14 rounded off the research we had done in preparation for the third stage in the conservation of Dutch video art collections.

The digital Betacam tapes have a factory guarantee of about ten years, and that has now almost been reached. So we have to switch to a new format. The Playout study focused on the conservation of digital video files.


PACKED: How many people are currently at work in the NIMk studio?

Ramon Coelho: Two, Mario Vrugt and myself. For some jobs we bring in freelancers too, such as large-scale tasks, encoding,15 spooling tapes and so on. For example, in this project Jata Haan is digitising the 1” tapes.

Mario does most of the actual conservation work. I provide him with support and am responsible for following up the conservation projects. Apart from that, I also do production work and editing for artists.

My colleague Mario’s background is also based on experience. He joined Montevideo as a systems manager. But in the past he had also made his own video programmes for the cable broadcasters. He has also learned a lot from me. He is a musician too, and uses electronics a lot.


 Digitisation of 1"C tapes (Mario Vrugt), Nederlands Instituut voor Mediakunst, courtesy: NIMK


PACKED: Your studio existed before you started conservation work. It always provided support to artists: for editing, setting up exhibitions and so on.

Ramon Coelho: That’s right. We also rented out equipment for a long time. For example, in the eighties there were not yet any Handycams.16 Because video cameras were so expensive, artists hired rather than bought them.

At that time it was important for the NIMk that for video artists, or artists in general, the whole production process received support: from the recording through editing to setting up an exhibition. It seems to me this is the important part of our work as far as they are concerned. We can offer them answers to a huge range of questions.

But it’s not only artists who can ask us questions, there are also art institutions, museums and suchlike. We stopped renting out video equipment a couple of years ago. But we do still have a lab where things such as HD-syncstarters17 are developed, devices that are not yet available on the market.


PACKED: Was the choice of having your own video studio made right at the start?

Ramon Coelho: No, not right at the start. Montevideo started as a video gallery. The first aim was to show video art. My father had worked for TV broadcasters. The gallery was launched on very limited funds, and the accommodation was small. But two more video player-recorders were soon added, and an editing device. But we only built a proper editing studio in the mid-eighties when a subsidy was made available for it. Since then the facilities have been maintained and updated.


PACKED: Has the studio’s work changed over the years?

Ramon Coelho: Yes, in recent years the main focus has shifted from providing artists with production support to conservation. In the eighties and nineties postproduction and renting out equipment were the most important activities. But nowadays more and more artists can manage for themselves. When we do postproduction work for artists now, it is more specialised work such as editing for high-quality HD productions. Artists of the old school who do not want to waste their time getting involved in computer programmes do still come to us for help.

But as well as that, our studio also provides support to the other departments of the NIMk. We are always ready to help the distribution department.18 For the last ten years we have mainly made DVD copies for them. We also provide support for the exhibitions19 held here in the building.


PACKED: So it has never been an option to contract out the copying of videos or even digitisation, as the Flemish institutions20 are now contracting it out to you under the BOM-Vl scheme? Is this connected to the specific requirements of video art, and the fact that the commercial video labs cannot really handle this?

Ramon Coelho: Yes. There is a different work approach in commercial labs. You experience the pressure of commerce, money and time much more there. It’s all expensive there, so it all has to go fast. The same applies to the television broadcasters. The production process follows a sort of cadenza. The director supervises the operators in a series of shouted instructions. This is not at all the sort of atmosphere artists want to do their creative work in. The working atmosphere is important. It is also important that it should be affordable and thus feasible for artists. Thanks to the subsidies, the prices we charge would be impossible in the commercial world.

Furthermore, over the years we have built up specific expertise for the arts sector which you do not find in commercial copying or editing companies.


PACKED: Do you know of any other places similar to the NIMk studio in Europe?

Ramon Coelho: No, not really. Some of its activities can be found here and there. We cannot see many comparable initiatives on the conservation front either.


PACKED: Do you sometimes have to contract jobs out because you cannot do them yourselves?

Ramon Coelho: Sometimes, but that is mainly a question of renting the equipment we use in exhibitions. As far as conservation is concerned, we can actually do it all ourselves. It’s just film that we contract out. But then film is not part of our area of work. We do have a couple of films in our collection, but the conservation work they need is done by the Nederlands Filmmuseum.21


PACKED: The conservation projects you mentioned before involved not only your own video collection but also those of other Dutch art institutions. Are those collections also kept in your storage space?

Ramon Coelho: Yes, the conservation masters belonging to the participants in the Video Art Conservation Project are kept here. Though there are two exceptions: the collections of the World Wide Video Festival22 and the Stedelijk Museum Amsterdam.23 They manage their video tapes themselves.

This storage is a service we offer museums because we have a climate-controlled storage space here and when requested can very easily make a DVD copy of the conservation master in our studio. The latter point is a major advantage for the museums.


PACKED: How many collections does the NIMk itself look after?

Ramon Coelho: We ourselves look after four collections, those of De Appel,24 Mickery,25 the Lijnbaancentrum26 and NIMk itself. And the NIMk is the result of the merger of two organisations: Montevideo and Time-Based Arts.27 All these collections can also be consulted at the NIMk.

But in addition we also look after the collections of several organisations that have taken part in our conservation projects.


 Storage of videotapes in a climate-controlled storage space, Nederlands Instituut voor Mediakunst, courtesy: NIMk


PACKED: You are now working on commission to the BOM-Vl project. You often take on such assignments for third parties. Is the communication and working relationship in this case similar to that in other commissioned projects?

Ramon Coelho: Yes, there is little difference. But if we carry out an assignment in the Netherlands it usually involves the conservation of an individual collection (e.g. the Jan van Eyck Academy28 and the Frans Hals Museum | De Hallen Haarlem29). For BOM-Vl we are digitising works from four separate collections at the same time.

Our own conservation projects have of course given us experience of large collective projects in which several collections participate. In the case of BOM-Vl, however, it is not we, but BAM.30 that is coordinating. I don’t see any major difference. Strictly speaking, this sort of large-scale project is bound to be somewhat bureaucratic.


PACKED: Is there a similar relationship between you and the client?

Ramon Coelho: Yes, there is a similar relationship between the museums and the NIMk. There is a certain trust. This means that no members of the museum staff have to be present. They don’t have to sit next to us in the studio all the time we are working on digitisation. But our work is always open. People can visit us at any time during the working process. We communicate clearly about what is going on in our studio. The fact that hardly anything ever goes wrong increases that trust.


PACKED: Do you already have any idea, as you make a start, of the average condition of the tapes from AMSAB, M HKA, SMAK and the Antwerp Municipal Archives?

Ramon Coelho: Yes, we carried out some random tests on the 1” tapes from AMSAB. The results were very good. I have looked at the M HKA tapes too. They include some very dusty tapes and some old U-matic tapes of a particular make. My experience enables me to guess the problems that may arise. We shall have to clean these tapes very well, but we have had enough experience of that.

I can also estimate the average processing time on the basis of other conservation projects. We operate at an average ratio of 1 to 2.5, meaning that the digitisation of 1 hour of various types of video material takes about 2.5 hours.


PACKED: How many tapes are you digitising for BOM-Vl?

Ramon Coelho: For AMSAB there are 139 tapes, or 105 hours, for M HKA 42 tapes or 18 hours 22 minutes, from SMAK 13 tapes or 5 hours 30 minutes, and from Antwerp’s municipal archives 41 tapes or 60 hours and 48 minutes. Altogether that’s 235 tapes or almost 190 hours. The formats we have received are 1” C, ¾” U-matic and VHS. Among the SMAK tapes, there is also a difference between PAL and NTSC tapes, both U-matic and VHS. This may also be the case with M HKA, because not all the documentation of their works is complete. As a result of this incomplete documentation, there is still a possibility of more time being necessary too. But in principle we can finish the job in the set period of two months.


PACKED: Is there a difference in content between the tapes from the art institutions, SMAK and M HKA, on the one hand, and the archives, AMSAB and the Antwerp Municipal Archives, on the other?

Ramon Coelho: Yes, the tapes from the SMAK and M HKA mostly contain works of art. The others contain mainly documents: recordings of concerts, events, and so on. They also involve an element of culture. The AMSAB tapes mainly contain television programmes, which probably also involve culture too.

So the tapes from the SMAK and M HKA are the only ones with autonomous art, to which our digitisation method, with its conversion to a 10-bit uncompressed format,31 is geared. This sort of high quality is not usually used for video documents. But we apply the same treatment to all tapes.


PACKED: So in principle you could apply a different method to the video documents, the ones that don’t contain any video art?

Ramon Coelho: Our method is oriented entirely towards autonomous art. Broadcasting companies and archives general use a different method that results in slightly lower quality. It’s a question of cost. A 10-bit uncompressed video file requires more storage capacity than a lossy compressed video file..32 Since broadcasting companies and archives often have to keep a huge amount of material, and since the quality is slightly less critical than in the arts sector, they often opt for another method.

So the method we use is the best one for video art. For video documents you could cut the cost of storage by opting for lower quality, such as the D10-50 format..33 This will not reduce the price of digitisation, only of the subsequent storage. However, I understand that the IBBT34 will store the files on LTO tape,35 and then storage is not very expensive either.


 The 1"C-tapes of AMSAB before digitisation, Nederlands Instituut voor Mediakunst, courtesy: NIMk


PACKED: If we run through your digitisation process, what are the first steps in your workflow?

Ramon Coelho: The tapes that come in first have to be inventoried and then stored in air-conditioned rooms at a temperature of 19° C and a relative humidity of 40%. Before we digitise ¾” U-matic, VHS and Betacam tapes, they are cleaned with RIT cleaning/evaluating machines. We do not clean 1” C tapes.


PACKED: What does a cleaning machine do?

Ramon Coelho: In a cleaning machine, the tape is passed under tension over tissue rollers. Loose and sticky particles are thereby removed from the tape. These particles can after all interrupt the contact between the tape and the playback head, which results in white or black lines (drop-outs). The sticky emulsion can also leave residues on the mechanical rollers, so that the tape no longer runs smoothly through the player.


PACKED: Why do you not consider it necessary to clean 1” tapes?

Ramon Coelho: We do not have a cleaning machine for 1” tapes. But our tests have also shown that it is not essential. We bought our Sony player for 1” C tapes specially for this BOM-Vl digitisation project. When I bought the machine, I did a test with a heavily powdered tape, and the reproduction of the video signal was immaculate. The 1” system uses such a broad video tape and the processing of the video signal is of such high quality that it is not troubled by a bit of dust. For example, I have just done a test with another tape, one of 22 years old, and the reproduction was perfect. Cleaning the tape, even if this were possible, would not make any visual improvement to the ultimate reproduction of the signal. We shall however have to clean the machine ourselves more often.


PACKED: Do you keep the masters of the works from your own collection at 19°C and 40% relative humidity too? These are after all often recommended as the ideal conditions for copies to be consulted and so on. But for the long-term storage of the masters 10°C is recommended, and 25% relative humidity.36

Ramon Coelho: There is some debate about this. Theoretically, it is possible to keep material longer in cold storage (even by freezing), but the risks also increase. The problem is that there is no carrier suitable for long-term storage. Not so much because of the storage life of the tape itself, but because of the change in the technological environment. It is mainly the players that die out. So you may be able to keep the tapes in good condition, but if the necessary equipment is no longer available after fifty years, there will have been no point in preserving the tapes well. It’s a risk.

If you keep the tapes in a cooler environment, you also have to have a sort of transition stage so that they can return to room temperature gradually. Otherwise there will be condensation. At low humidity, you also risk various side-effects such as static electricity, which attract dust. These are risks you have to take into account when deciding on the storage conditions. The most important element of storage conditions is constancy. It is the fluctuations in temperature and humidity that harm the material most.


PACKED: Let’s go back to the digitisation process. Good connections between the various pieces of equipment are crucial. Can you tell us something about that?

Ramon Coelho: Yes; to start with there are several video systems. Such formats as ¾” U-matic LB, Betamax,37 VHS and Video838 used composite video, a colour signal. This composite video signal contains both information on the brightness (luminance) and the colour (chrominance) of the image. Such later systems as U-matic HB, U-matic SP, Hi-8 and S-VHS39 use component video. These component video systems record the video signal in two components. The luminance and chrominance signals were written onto the tape separately. This resulted in a sharper picture and better colour distinction than in the older composite systems. When the signal is transferred, special cables have to be used to make use of the advantages of this system. In the mid-eighties Sony and Panasonic launched a second generation of component formats (including Betacam) in which the video signal is composed of three elements: one for the luminance and two for the colour information. These later video formats were better quality than the earlier ones. They also suffered less from loss of quality when copied.

All video recorders have a composite monitor output, called ‘video out’. However, if this connection is used for transferring signals when digitising, the advantages of the component system are cancelled out. So it is very important that the pieces of equipment are correctly connected.


 An overview of the connections of the various pieces of video equipment, Nederlands Instituut voor Mediakunst, courtesy: NIMk


PACKED: The players are linked to the Time Base Corrector (TBC) and to the audio mixer using the best possible connectors. Can you explain what the TBC is used for?

Ramon Coelho: The reason we use a TBC is that most older video signals are not sufficiently stable to be recorded well on modern video equipment. Among other things, a TBC corrects the timing of the video signal and passes it on again one frame later (1/25 of a second) at a stable frame rate. At the same time, a TBC enables you to adjust the gain,,40 the black level,41 the chrominance and the colour phase.

The most important difference between the various TBCs we use at the NIMk is in the video signal inputs and outputs. One is component, the other is composite. And U-dub, a TBC that can only handle U-matic dub. The TBC we use most is an AVS EOS standard converter. It can handle composite, component and Y/C.42

But some unstable signals, especially on tapes from the ½” era, cause problems when a modern TBC is used. A modern TBC does not take into account that there can be such great fluctuations in a video signal. When a particular TBC does not reproduce a video signal well, we can use another type that is able to handle these extremely unstable video signals. There are many different ways that electronics may react to particular fluctuations. In the worst cases we can also use an M-10 mixer. However, this device does not really make the video signal any better, since part of it is eliminated. But if the signal on a tape can only be reproduced with the help of an M-10 mixer, that’s better than no picture at all.


 Checking the colour bars (Jata Haan), Nederlands Instituut voor Mediakunst, courtesy: NIMk


PACKED: And what is the following step in the process?

Ramon Coelho: The tape that is to be digitised is run so that the video and audio signals can be adjusted. The device is first adjusted using any test signals there may be on the tape. The tape is then calibrated in several places using a waveform monitor, a vectorscope and an audio peak meter. If it appears that the signals are higher or lower than the agreed EBU levels,43 the various parameters are adjusted. The original signal is also compared optically to the corrected signal using two identical studio monitors. If it is clear that certain levels have been intentionally kept high or low by the maker or artist, this will be taken into account. In general, the programme or work as a whole will be digitised using the settings we have reached in this way.

We take note of the black level, the video gain and the chroma gain or saturation of the video signal. In addition to the colour phase, the chroma delay is also adjusted so that the luminance and colour signals are positioned equally. If the video signals are poorly reproduced because the signal has weakened, or was once badly copied, then as I have already mentioned, several types of TBC are used, each with its own specific way of processing the signal.


PACKED: And how is the sound copied?

Ramon Coelho: Stereo signals are copied directly to the corresponding channels in the new format. Mono signals are copied to both channels in the new format. An audio delay unit44 makes sure the audio and video signals are synchronised again after the processing of the video signal. As I have already mentioned, a TBC causes a slight slowing of the video signal. So the sound signal has to be slowed to the same degree.


PACKED: How are the TBC and the audio mixer connected to the rest of the equipment?

Ramon Coelho: The outputs of the video and audio signals are connected to the Digital Betacam Recorder (DVW 500P). This machine converts the analogue signals into a high-quality SDI stream. The SDI output is connected to the MPEG/AVI workstation. This HPxw8400 workstation is equipped with 2TB of striped disks and a PCI Express slot. To this PCI Express slot we connect the Multibridge Pro capture board that converts the SDI stream into uncompressed AVI files. This AVI format (uncompressed YUV 10-bit 4:2:2) results in about 93GB per hour of video. The SDI output of the Multibridge Pro is in its turn also connected to the measuring device and the studio monitor so that the process can be checked while it is taking place. The files themselves can also be subjected to random checks.

We also have the option of being able to filter the video signal for noise and video artefacts using the Snell & Wilcox CPP1000,45 but we are not doing that on this project. The reason is that this sort of filtering is not considered to be a sound conservation treatment. It is after all irreversible.


PACKED: Are notes made when digitising, if for example peculiarities are noticed or there are unexpected complications?

Ramon Coelho: Yes, things like that must of course be noted down. Otherwise the information would be lost, and someone may have to sort it out again in the future. All the information about the source (the original) and the new digital video file is recorded. It is part of what we call the metadata.


 Input of metadata (Jata Haan), Nederlands Instituut voor Mediakunst, courtesy: NIMk


PACKED: Do you then give this information to the owners of the tapes?

Ramon Coelho: Yes, I assume we do. It seems to me a good idea to keep it all together. At present we still have to decide how we are going to make a record of the data. We have received an xls document from the owners that includes such information as year, length, original format, comments, etc. We could add our observations to that. But we can also use our special databank that has a whole range of fields for this purpose. About ten items are stored. Experience has shown that this covers every need.


PACKED: What carrier do you use to give the video files to the IBBT so they can input them into the BOM-Vl Demonstrator and also provide the owners with copies?

Ramon Coelho: Each working day the digital video files will be copied without compression to an LTO-4 data tape. These data tapes are then given to the IBBT when everything has been completed.


PACKED: What happens to the NSTC tapes?46 Are they transcoded to the PAL system ?47

Ramon Coelho: No, we do not transcode anything. Transcoding is not considered a sound conservation treatment either. After a, like filtering, it is irreversible.


PACKED: In Belgium it has become hard to find playback equipment for ¾” U-matic and the various 1” formats that still works. What’s the situation in the Netherlands?

Ramon Coelho: Our studio is rather like an island. I can’t see anywhere else in the Netherlands that has such equipment. That’s also why it’s a good thing we’re here. As far as the 1” C format is concerned, we very recently bought a Sony BVH 2000-PS that is still in very good condition. Equipment like that is now extremely hard to find. We ourselves still have a stock of equipment for ¾” U-matic. We also regularly receive these machines from people and institutions that are going to move or have to have a clear-out. But it is obvious that it is becoming increasingly rare. The condition of the equipment will also deteriorate, and the parts will be increasingly difficult to find.

If you take the conservation of your collection seriously, you shouldn’t wait too much longer before digitising these formats. It will only become more difficult and expensive.


PACKED: Is it a matter of just a few years before these formats finally go out of use?

Ramon Coelho: The digitisation of ¾” U-matic may still be possible in 10 years’ time, but the question is at what cost, effort and risk? This is one of the major reasons why digitisation is extremely urgent. And the same certainly applies to the 1” format. The SMAK, M HKA, AMSAB and Antwerp’s Municipal Archives were very wise to decide to use the BOM-Vl project to digitise their old formats.


PACKED: It is recommended that the old video tapes should not be thrown away immediately after digitisation, but should be kept for a while. Is this good advice?

Ramon Coelho: Yes, definitely for art collections. It doesn’t add much to the cost to keep these tapes for a few more years. It’s best to keep them several years longer until you are sure you have taken the right decisions during the digitisation process. This may sound a little arrogant, but, given the equipment that is still available, the digitisation method we use here is the best possible. The quality we offer will not improve in the future. The quality will at best simply remain the same.


PACKED: In this case, one good reason for keeping the tapes for a while seems to me to be the risk involved in storing the files. After all, art museums in particular as yet have little experience with tapeless storage.

Ramon Coelho: If you make the wrong choice in that respect and have to do the digitisation all over again, you will of course need the tapes. But I can think of a second reason. In art collections, the video tape has a value as an object. After all, it is an object on which you often find traces of the artist’s hand, such as the handwritten label on the box or the cassette. This too has a value, not only the video signal itself.


PACKED: A third reason might be that a museum keeps them as a form of reference. If you let go of the old tapes and the necessary equipment to play them, you can never again show what the work originally looked like.

Ramon Coelho: That’s right. That’s another thing that’s important in art, certainly in installation art, where the equipment is part of the physical arrangement of the work. We have already had to say goodbye to the old playback equipment: monitors and projectors with cathode ray tubes. The old CRT monitors we are still using are only 10 to 12 years old, but we no longer have any left from, let’s say 20 years ago. From the point of view of art history, it may also be important to take the trouble to keep the original tapes. An artist or curator may one day want to show the work in its original form.


 Checking the start of the videotape (Mario Vrugt), Nederlands Instituut voor Mediakunst, courtesy: NIMK


PACKED: What are the most common problems with old magnetic carriers such as 1”, ¾” U-matic and VHS? Sticky shed, mould…?

Ramon Coelho: Fortunately we don’t often come across mould. The tapes would have to be kept in very poor and damp conditions to cause that. The biggest problems arise out of the chemical composition of the video tape itself. The components of a tape, such as the base film and the binding coat are susceptible to chemical change in the course of time. The most frequent result of this is stickiness, especially in ½” open reel tapes. The video signal is usually still intact on the tape, but the chemical process means the tape doesn’t run smoothly through the playback machine. This means some tapes cannot be played in their entirety.


PACKED: Can you remove this stickiness by cleaning the tape?

Ramon Coelho: Yes, we do clean such tapes. We have an RTI cleaning machine for ¾” U-matic, VHS and Betacam SP. And for ½” open reel tapes we made a cleaning machine ourselves. The stickiest tapes are cleaned five to eight times before everything has been removed and they run smoothly through the playback machine again. This cleaning does not remove the magnetic information.


PACKED: You sometimes hear from video labs that tapes are ‘baked’. Do you do that?

Ramon Coelho: No, we haven’t yet used that method. The RTI dry-polishing machines we use means it’s not necessary. All we do is pass the tape over tissue under a certain amount of pressure. The notion of ‘baking’ appeals to the imagination, of course. The word itself is rather an exaggeration. The tape has to be heated to 40°C for 24 hours. That drives off the moisture. The tape then runs more flexibly through the machine again. But you can only carry out this ‘baking’ once, at least if it’s the method I learned about in the nineties from someone who did video conservation at the NOB.48


PACKED: Does the information on the tapes gradually disappear?

Ramon Coelho: Yes, but very slowly. But the interpretation of the information is different in modern equipment. In the past, a video monitor accepted signals that were not so stable and still displayed a good picture. A modern TBC or a digital recorder needs a much more precise signal to give good reproduction. Compared to modern equipment, much greater signal fluctuations were accepted.

So it is not so much a question of the signal fading as a change in the standards for a signal. The reason why old signals can no longer be interpreted and displayed by modern equipment has more to do with the industry than the carrier itself. The signal is in most cases still contained in the carrier. The problem lies much more in the incompatibility of playback and display equipment.


PACKED: And what about the physical deterioration of the equipment itself?

Ramon Coelho: There is also deterioration of the equipment and of the components they comprise: not only the belts and the rubber but the electronic parts too. In the course of time, chemical processes change the values of the electronic components too. Actually the greatest danger lies in the deterioration and obsolescence of the equipment.


PACKED: The knowledge needed for the maintenance of the old machines is vanishing too. How do you maintain your equipment?

Ramon Coelho: We only do the minor maintenance ourselves. For the major work we rely on external experts. It’s no problem for modern equipment, but for the 1” machine, for example, we also know a specialist who has both the knowledge needed and the spare parts. We don’t replace any parts ourselves, nor do we swap them between machines. We don’t need to do it because we have enough old machines to choose from.

It would not be a bad thing to adapt the machines for the ½” open reel format. Sony does this. The system is being changed because the tape transport in the player is much too heavy. It is possible to improve it. Some of the rollers are fixed and it would be better if they revolved so that the transport of the tape through the machine ran more smoothly. It’s possible to modify this. Since, fortunately, we do not have to digitise many ½” open reel tapes any more, we have until now paid little attention to this.


PACKED: You have already digitised the open reel tapes from the Dutch collections in the first and second stages of conservation, I believe?

Ramon Coelho: Yes, in the first stage of conservation we transferred them to Betacam SP. In the second stage this was then transferred to digital Betacam. So we already did the actual transfer of the open reel tapes in the nineties. It was an awful job. Copying an open reel tape has a processing time ratio of 5 to 1, which is twice as long as copying a ¾” U-matic tape.


 Screenshot of a programme from the collection of AMSAB, Nederlands Instituut voor Mediakunst, courtesy: NIMk


PACKED: How do you deal with the incorporation of a new individual work or self-contained collection into your own collection?

Ramon Coelho: The description of the intake is done by the NIMK’s distribution and collection department. They accept new work from artists after a selection procedure. At the request of my department, a certain type of master has to be provided. The artist gives us what he can, preferably in a format that is suited to our production environment. A very wide range of formats currently comes in. Tape is used less and less. We increasingly receive video files. We have large servers to store them on.

I am only talking about our own collection, the active collection. But as I have already said, we also store the video collections of several other institutions. Some of them purchase works for their collections and then bring us one or two tapes every month. They are then registered.


PACKED: Are the new tapes that are accepted first examined?

Ramon Coelho: No, they are not systematically examined. The tapes are wound through once a year, however. In practice a DVD copy is often made of the tapes and then there is a sort of check-up.


PACKED: There is some controversy about the annual winding through, isn’t there?

Ramon Coelho: It is always better to regularly wind the tapes through, but of course you have to do it properly. You mustn’t do it on an old machine that may cause scratching. In some systems the tape runs lightly over the playback head. This is what the tape is made for. If the machine is in good condition, this does no harm to the tape, and if it does any harm at all it is to the playback head.


PACKED: You might say that every time the tape runs over the playback head there is the risk of damage, or that a small number of particles from the top coating are shaved off.

Ramon Coelho: That applies mainly to machines in poor condition. A new playback head may also be a little sharp, take off a little of the top coating and thereby become dirty. Video systems are designed to be able to play the same tape hundreds of times. Winding it lightly over the playback head should never have a negative effect on the tape.

But I understand the controversy. This winding through started with audio tapes which, if they have stayed on the shelf for a long time, experience print-through. The fact that the magnetic information has an effect on the adjacent winding produces an echo. This is avoided by winding the tapes through once a year.


PACKED: But video tapes don’t seem to suffer from this print-through. So why is it still important to regularly wind the tapes through?

Ramon Coelho: Firstly in order to prevent the tape sticking together, and secondly to redistribute the tension equally over the whole tape and thereby avoid damage by tension and traction. This tension arises mainly when a tape is poorly stored and subjected to temperature fluctuations. The tensions arise on the inside of the spool because the tape stretches and shrinks under the influence of its environment. As far as I am concerned, annual winding through is to be recommended, but it does mean a lot of work if you have a large collection.


PACKED: It is always recommended that video tapes be stored upright. Why?

Ramon Coelho: The edges can be damaged if the tape drops to one side of the spool. It may be pressed and creased, especially along the edges. In some systems there is a lot of important information along the edge of the tapes, such as the time code.


 Digitisation of 1"C tapes (Jata Haan), Nederlands Instituut voor Mediakunst, courtesy: NIMk


PACKED: How do you avoid overlapping in your various conservation projects? There must surely be works in different collections that have the same title and may or may not be identical.

Ramon Coelho: This was not considered beforehand in the first stage of conservation. So all sorts of works were copied twice. Each collection was copied separately. Which meant that the works that appeared in several collections were also copied several times.

For the second stage of conservation we did put together what we called a ‘doubles collection’ beforehand. In the end only the best example of a particular work was copied to digital Betacam and the new conservation master is accessible to all the institutions that possess that work. We shall take a similar approach in the third stage of conservation. So doubles are avoided by making arrangements with the holders of the collections. It is of financial benefit to the institutions to take part in this. It also means the best version is available to all the collections.


PACKED: Are all the data also in a central databank? Or do you avoid overlaps by comparing separate lists?

Ramon Coelho: There is a lot of paperwork involved, but databanks too. It is above all a question of manual comparison. There are four factors that show whether it is the same work: title, duration, colour or black & white, and film or video. In the course of the conservation process itself, it may turn out that certain conclusions regarding overlaps are not correct. We can then review these earlier decisions.


PACKED: Apart from avoiding doubles, did you learn any other lessons from the first stage of conservation?

Ramon Coelho: Yes, in the first stage no editing was done. During the first stage we transferred works in all sorts of less familiar formats (e.g. ½” open reel) to Betacam SP. When we did this, it often happened that after five minutes the playback head was dirty and we had to interrupt the copying process. It was often impossible to copy a work entirely in one go. It could often only be done bit by bit.

The process often had to be interrupted to clean the playback head. Afterwards we restarted with a certain amount of overlap. In order to be able to put everything back together again neatly afterwards the start of the second piece overlapped the end of the first piece. We did of course record in the databank which works had been copied in one go and which in sections. In the latter case we also noted the time codes of the various sections.

In the second stage of conservation we had a set-up that could be controlled on the basis of the time code, and were able to edit together those works that had had these problems in the first stage in their original form on the basis of the time codes. But this happened only rarely. It was less than 2% of the works.


PACKED: Did you learn any other lessons?

Ramon Coelho: When carrying out the first stage we forgot something: when processing video through a TBC the video signal is slowed down. It comes out one frame later and that means the audio signal was always a step ahead. So after the first stage of conservation the audio was one frame ahead. So in the second stage we used an audio delay unit to add two frames. This meant we slowed the audio signal by two frames to restore the lip-sync.


PACKED: Were any lessons learnt from the second stage, the transfer to digital Betacam, that were useful for the third stage?

Ramon Coelho: Clear lessons were learnt from the first stage that helped in the second, but little was learnt from the second that could be used in the third. In my view, no errors were made in the second stage, so there were no real lessons to be learnt. We just have to carry on as we are. But the third stage will be characterised by a different workflow: from digital Betacam tape to a digital file format. It will be a more clinical process. The analogue formats have already been calibrated and digitised to digital Betacam.


PACKED: This intermediate stage using digital Betacam was not used for the collections from AMSAB, M HKA, SMAK and the Antwerp Municipal Archives. In this case it goes straight from an analogue tape format to a digital file format.

Ramon Coelho: This workflow is new for us. We have already carried out tests. But we are ourselves curious how the work will go for the whole collection of tapes. When copying from Betacam SP to digital Betacam we had editing equipment available. It was possible to say ‘this is my starting point and it’s going wrong, I’ll pick it up again later.’ This is not possible when creating digital video files. The workflow is different. You may have to edit a file afterwards from time to time, or do the file again…


PACKED: We talked about the ageing of equipment, resulting in obsolescence and physical deterioration. Just as in the outside world, the equipment in your studio is also rapidly ageing. At a certain moment you too will surely have to give up working with analogue tapes. Have you any idea how long you will have to keep your present equipment going to avoid works being lost in the transition to the tapeless era?

Ramon Coelho: We ourselves are in a comfortable position because the work in our own collection that was originally made on analogue video formats has almost entirely been secured on digital tape formats, which are easier to encode. But there are other collections in the Netherlands, and certainly in Belgium and the rest of Europe. We are pleased to provide these digitisation services, but, with only a few exceptions, we have no fears about the digitisation of our own collection.

But the management of collections remains a human matter. We have just cleared up a cupboard full of documentation and found several tapes that are considered to be masters and should therefore already have been conserved. I would say that the analogue equipment should remain operational for another five years. The longer the better. It is a fantastic facility. But it has to be manned by people with expertise and it has to remain affordable.


 Digitisation to AVI uncompressed format, Nederlands Instituut voor Mediakunst, courtesy: NIMk


PACKED: You have only just completed a study (Playout) in preparation for the third stage of conservation. What are the main questions that still remain unanswered?

Ramon Coelho: The last big question concerns the storage of the digital video files. Storage on tapes is a reliable and affordable solution, but we are looking for a form of hybrid storage where storage on tapes is combined with storage on a server. That also seems to us the best way of being able to control the storage situation. So it is the safest form of storage. A major problem about storage on servers is that the hard disks have to remain constantly in operation, thus using a lot of energy, which doesn’t make them very environmentally friendly. We anticipate that we shall need a storage capacity of 100 TB. Using hard disks that are constantly in operation means this is environmentally irresponsible. The market has not yet reached the point where it can offer disks that can stay still. We are still awaiting this development.

Another thing that is still uncertain is the calculation of the processing time. The experience we are gaining now from providing services for BOM-Vl will help us refine the calculation of processing times even more.


PACKED: And what were the results of your study into the use of the codec?

Ramon Coelho: The final conclusion is that we are still dependent on the industry. There is no open source codec that is sufficiently well supported. It is the industry that has the most resources to develop new things and we just have to follow them. The codec we use is the V-210. We have no choice. This is the codec the Blackmagic capture card uses. It is a fairly widely used codec that is also supported by Sony and others.

So we shall have to continue keeping an eye on whether future hardware still supports our codec. Fortunately compression is not involved here. But the codec does for example determine the arrangement of the data. As soon as you see that the codec will be going out of use, you can transcode the data to another codec with no loss.


PACKED: What about digital-born material? Artists no longer supply you with new works on analogue video tapes but on digital tapes and also increasingly on hard disks.

Ramon Coelho: Our second conservation project, in which we digitised analogue tapes, was completed almost ten years ago now. So as far as we are concerned, the analogue era is over. We have not yet developed a conservation strategy for the DV formats. It is reassuring though that the DV format is an open source format, so you can keep them and continue to play them back at any time. Compression is used in DV formats. We assume that we shall not be expanding these formats to the uncompressed AVI format that we shall use for the works originally made on analogue formats. The DV codec can be used, and the required storage capacity is smaller than for the uncompressed AVI format. No conversion has to be done.


PACKED: Does that mean that the works on mini-DV deposited here by artists have always been stored on mini-DV? Or have they been transferred to digital Betacam?

Ramon Coelho: Yes, the original mini-DV cassettes have been kept as masters. But submasters have also been made, first on Betacam SP and later on digital Betacam. So the original mini-DV cassettes are still here. It was only recently that we considered that we ought to store these tapes in very good conditions so that they remain in a good state and can be captured in the near future to make a tapeless video file.


PACKED: And what about the works artists have handed in on a hard disk? Are they kept on a server?

Ramon Coelho: Yes, they are, and submasters are also made on digital Betacam. But it is no longer possible to copy works in High Definition49 resolution to digital Betacam. These files simply remain on the server. The server is constantly expanding. But we also have a RAID system and a back-up on tape. All the files in the master files partition are considered to be masters. So there is no longer any tangible physical master of these works. The number of such works is not very large, but it is increasing.


PACKED: So for you the question remains whether you keep them only on the server or also copy them to tape.

Ramon Coelho: I have storage for edited files and a file server for master files. The method I have devised is to consider annually whether we are actually going to use the files stored in these locations. If the answer is no, we can move them to data tape.


PACKED: These two directions, on the one hand the transfer of analogue and digital tapes to tapeless files, and on the other the storage of the tapeless-born files, will one day surely merge and become a single entity.

Ramon Coelho: Yes, it will all have to be made uniform. But because of the differences in resolution, the formats will probably not be combined. It will never become one single video format. They will remain separate formats. But the collection, with its various formats (partly due to the use of a databank), will indeed become a single whole.


 Screenshot of a programme from the collection of AMSAB, Nederlands Instituut voor Mediakunst, courtesy: NIMk


Addendum (e-mail correspondence on 1/7/09):


PACKED: The digitisation of the video tapes from AMSAB, M HKA, SMAK and the Antwerp Municipal Archives was completed yesterday. Can you tell me briefly how it went? Let’s start with the AMSAB tapes.

Ramon Coelho: Most of the tapes to be digitised originated from the AMSAB. They comprised 139 tapes in 1” C format. They turned out to contain television programmes produced by the SOMSOM50 for the BRT51 between 1986 and 1996. We were fortunate enough to have been able to buy a very good Sony BVH2000 machine, which we used to digitise these tapes. Some of them were not in good condition. There was powder on the outside of the tape. Nevertheless, our machine rarely had any trouble reproducing the video signal, as if it were almost new. We were ourselves amazed at the quality that these old tapes, from 13 to 23 years old, were still able to produce. Unlike the other formats, the composite video signal of the 1” machine went straight into the Multibridge Pro capture board without using a TBC. The colour bands on these professionally produced works could simply be adjusted in the Multibridge Pro capture board application.


PACKED: And what about the rest?

Ramon Coelho: It was among the 42 tapes from the M HKA that we found the most surprises, in terms of both content and quality. Several U-matic tapes from the seventies were in very poor condition. Some tapes were broken, others were even folded double over their entire length.

The 41 tapes from the Antwerp Municipal Archives were the most varied in quality and format. They did not present any problem, however. But the duration of the programmes was sometimes unpredictable. The 13 tapes from the SMAK were not so old and did not give us any problems either.


PACKED: You met the deadline perfectly. Did the time you had estimated for the job turn out to be right?

Ramon Coelho: Yes, the project was to a certain extent carried out against the clock, but our estimate of a working time 2.5 times longer than the total playing time of the tapes turned out to be correct.


[Translation: Gregory Ball]





  • 1. On the cultural side, a broad range of organisations was involved, including the FARO, BAM, VTi and Muziekcentrum Vlaanderen information and documentation centres. Participants from the media sector include the public, commercial and regional broadcasters. The IBBT and the VRT Medialab help provide the academic framework.
  • 2. Interdisciplinair Instituut voor Breedbandtechnologie. See:
  • 3. Amsab - Instituut voor Sociale Geschiedenis. See:
  • 4. Museum of Contemporary Art in Antwerp, see:
  • 5. S.M.A.K, Municipal Museum of Contemporary Art, in Ghent. see:
  • 6. Stadsarchief Antwerpen. See:
  • 7. Other cultural institutions including the Royal Belgian Film Archives and the Muziekcentrum Vlaanderen have already digitised films and audio works.
  • 8. BAM (Instituut voor beeldende, audiovisuele en mediakunst. See:
  • 9. FARO (Vlaams steunpunt voor cultureel erfgoed). See:
  • 10. Betacam SP is an analogue video format that came onto the market in 1986 and consists of a ½ inch magnetic video tape in a cassette. It was generally considered to be a stable format of high quality.
  • 11. ½” open reel is an analogue video format introduced in 1965. The ½-inch tape is not inside a cassette but on an open spool. The tapes were used in combination with the first portable video recorders and were widely used by artists, lecturers and activists. Broadly speaking, there are two categories of ½” open reel: CV (Consumer Video/Commercial Video) and AV (EIAJ Type 1). Although the tapes look identical, the players are not compatible.
  • 12. The Stichting Behoud Moderne Kunst (SBMK) has since 1995 been engaged in projects in the field of conservation and management of contemporary visual art. The aim is to develop good practices to the advantage of all interested parties. See
  • 13. The institutions involved were the Van Abbemuseum, De Appel, Museum Boijmans Van Beuningen, Groninger Museum, Instituut Collectie Nederland, Kröller-Möller Museum, Nederlands Instituut voor Mediakunst, Montevideo/Time-Based Arts, Rijksakademie van beeldende kunsten, plus the Mickery Collection and the Stedelijk Museum Amsterdam.
  • 14. Playout was a study of new techniques for conserving collections of video art in the Netherlands and making them accessible. The aim of the project was to find the best method of storing the works of video art in Dutch museums and making them available online. The results of the project were presented in spring 2009.
  • 15. In this context, encoding means converting a digital tape to a tapeless digital format.
  • 16. Handycam is a trade mark used by Sony for its range of camcorders (portable combined camera and recorder).
  • 17. An HD-syncstarter is a device used for the synchronous display (accurate to the frame) of several High Definition videos on several screens.
  • 18. In order to enable a broad public to learn about media art, the Nederlands Instituut voor Mediakunst pursues an active distribution policy. Video tapes and media installations from the collection can be seen at domestic and international festivals, events and exhibitions, in galleries, museums and other art institutions.
  • 19. In its gallery space, the NIMk holds long-running group and thematic exhibitions such as solo presentations, retrospectives and shows in association with other institutions. These presentations take a museum-like approach. They offer a clear insight into a particular oeuvre or subject. In between the long-running exhibitions there is also time for more experimental presentations such as short exhibitions, symposia, screenings, live performances in sound and image, and test set-ups by artists and students.
  • 20. i.e. Stedelijk Museum voor Actuele Kunst in Ghent, Museum voor Hedendaagse Kunst Antwerpen, AMSAB-ISG in Ghent and Stadsarchief Antwerpen.
  • 21. Nederlands Filmmuseum. See:
  • 22. The World Wide Video Festival was a media art festival that was held every year from 1982 until 2004. See:
  • 23. See:
  • 24. De Appel is an internationally oriented arts centre in Amsterdam which since 1975 has functioned as a platform for the study and presentation of contemporary visual art by means of exhibitions, publications and discursive ‘events’. The NIMk looks after De Appel’s video collection, which dates from between 1973 and 1983. See
  • 25. In the 70s and 80s Mickery was well-known as an experimental theatre in Amsterdam. Its founder, Ritsaert Ten Cate, often invited international theatre companies to perform in this small theatre. In 1984, Ten Cate decided to include video in his programme for the next four seasons because he wanted to experiment with what television had to offer him as a theatre producer.
  • 26. The Lijnbaancentrum was founded in 1970 to provide a low-threshold exhibition space in Rotterdam’s shopping centre and to stimulate the use of video. The NIMk looks after the Lijnbaancentrum’s video collection, which dates from 1970 to 1982.
  • 27. Time-Based Arts was set up in 1982 as an independent organisation.
  • 28. Jan van Eyck Academie. See:
  • 29. De Hallen Haarlem. See:
  • 30. BAM is the institution for visual, audiovisual and media art. It is a documentation and information centre for the arts sector in Flanders. See:
  • 31. This is a format in which no data compression is used. 10-bit refers to the depth of colour, this being the measure used for the number of bits used to encode the colour of a pixel. The higher the depth of colour, the more different colours can be encoded.
  • 32. Data compression means representing digital data using fewer bits than the original. In lossy compression, the compression is not exactly reversible because part of the data is lost. Because video files are mostly large, they usually use lossy compression.
  • 33. D10/IM X-50 is a standard based on the MPEG2 compression method used by television broadcasters and also the Stichting voor Beeld en Geluid. It is an attractive format because the files are relatively small while retaining fairly high quality. For the broadcasters’ archives, this choice can be defended for economic reasons. However, at the NIMk we are concerned with video as an autonomous work of art: the video signal is the work of art, or is an important part of a work of art.
  • 34. The IBBT (Interdiciplinair Instituut voor Breedband Technologie) is an independent research institution that has been commissioned by the Flemish government to stimulate ICT innovation. The IBBT team offer businesses and organisations active support in research and development and for this purpose bring together a wide variety of companies, levels of government and non-profit organisations for research projects. See:
  • 35. Linear Tape-Open (or LTO) is a standard developed in the late nineties for storing data on magnetic tape.
  • 36. For example, in Dietrich Schüller’s TAPE publication Audio and video carriers (see: ) or the section on the video preservation of IMAP in the EAI Online Resource Guide for Exhibiting, Collecting & Preserving Media Art (see: )
  • 37. Betamax was an analogue video format that used ½” tape in a cassette and was developed by Sony for the non-professional market. Despite being better quality, it lost the commercial struggle with the VHS format developed by JVC.
  • 38. Video8 was developed as a non-professional format and its quality was comparable to VHS. This non-stable format was often used in smaller camcorders.
  • 39. Although S-VHS cassettes look similar to VHS ones, they provided better quality sound and image. The S-VHS format never really took off.
  • 40. Gain is the video level, or the strength of the incoming video signal.
  • 41. In video, the black level is the luminance of the darkest (blackest) part of a picture or the luminance at which no light is radiated by a screen, thus resulting in a black screen. Video screens have to be calibrated so that the black displayed corresponds to the black information in the video signal. If the black level is not correctly adjusted, visual information in a video signal may be shown as black, or black information as grey.
  • 42. Y/C is also known as S-Video or Separate Video. It is an analogue video signal that transports video data as two separate signals: lumen (luminance, Y) and chroma (colour, C). Y/C differs from composite video, which transports visual information as a single low-quality signal, and from component video, which transports visual information as three separate high-quality signals. Y/C or S-Video transports standard definition video, but no audio on the same cable.
  • 43. The levels set as a standard by the European Broadcasting Union.
  • 44. An audio delay unit slows down the audio signal.
  • 45. The Snell & Wilcox CP1000 is a compression pre-processor, a device that processes the video signal (by filtering out image noise, among other things) before it is compressed. The filtering results in a better-quality visual image because image noise and related video artefacts can lead to annoying blockiness and speckle effects. Filtering also has a beneficial effect on compression. When compression is carried out, no distinction can be made between image noise and movement, so that the image noise and other artefacts are also compressed; this results in a larger bandwidth being required. If the image noise and the artefacts are filtered out of the signal first, compression will be run more efficiently.
  • 46. NTSC (National Television Systems Committee) is the American standard for the video colour system. It uses 525 picture lines which are scanned at a speed of 30 images per second.
  • 47. PAL (Phase Alternate Line) is the European standard for the video colour system. It uses 625 pictures lines which are scanned at a speed of 25 images per second.
  • 48. NOB (Nederlands Omroepproductie Bedrijf) was a Dutch company that provided facilities for television productions. In 1988 the former logistical department of the NOS separated off as an independent company, and this became the NOB. In 2002 several parts of this company were sold and the rest was divided up into three new companies: Dutch View, Ciris and NOB Cross Media Facilities. The last of the three was later also sold and is now called Technicolor Nederland.
  • 49. The term High Definition (HD) currently refers to video formats with a resolution higher than Standard Definition (SD). At the moment there are two HD resolutions, 720 and 1080 picture lines.
  • 50. Socialistische Omroepstichting (socialist broadcasting organisation).
  • 51. Belgische Radio- en Televisieomroep (Belgian radio and television broadcasting organisation), which in 1991 became the BRTN (Belgische Radio- en Televisieomroep Nederlands) (BRT/Flemish) and since 1998 has been the VRT (Vlaamse Radio- en Televisieomroep) (Flemish radio and television broadcasting organisation).
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