In archival work, all audiovisual formats are at risk, and for all kinds of reasons. When it comes to analogue video and its many different formats, we not only face physical deterioration of the tapes but must also battle with obsolete technology, dying skill sets and the retirement of highly trained engineers. The latter concerns are what sets videotape apart from a lot of moving image material, as archivists and conservation specialists are in a race against time to get the content off tape before it is too late.
In this article, I will concentrate on outlining two significant videotape formats from the first phase of the medium’s history – the era of the development of broadcasting – when video was another word for television.
The 2″ Quadruplex Tape
In the beginning, there was the 2″ Quadruplex “quad” Tape (2 inches wide), introduced in 1956 and used by broadcasters into the early 1980s. The casing can range from plastic containers with handles to cardboard carriers resembling a wide takeaway pizza box.
Dirt building up on the heads during scanning, signalling that the tape is not clean enough for transfer.
A lot of quad tapes don’t look as pristine as the one in the photo and, even if they do, all of them require cleaning. Dirt, mould, oxide shedding, binding issues, glue leaks and deterioration come in many forms – some of it subtle to the eye but significant enough to damage the heads on a quad machine or prevent playback altogether.
The four heads on the spinning head wheel of the playback machine are what the term “quadruplex” stems from. When these spin, they produce a method of reading the tape called quadrature scanning. This is why whenever a quad tape clogs during playback, the screen shows the image being impacted in four horizontal lines (as shown on the right).
Shiny black confetti.
While cleaning (on a quad cleaning machine), further issues arise if deterioration has occurred, such as a tape sticking and refusing to move, or shredding its edges into shiny black confetti (see left), signalling the opposite of a party for the specialist in charge of it!
In some cases, the quad tapes are so dirty or deteriorated that they require baking in an oven for three days (different practitioners may adhere to varying durations) and then have a window of a few days to be played before they revert to their original state. The scientific reasons behind this solution have been debated for years by the industry, but the most common theory is that the baked tape’s temporary removal of moisture facilitates a better transfer.
2″ quad tape playback machine.
To make things more challenging, once quad tapes are fit for playback, not all of them will play on the same 2″ machine and, if they do, customised setups are required for playback depending on things like colour, line standards (e.g. 405- or 625-line television) and even the broadcaster the tape originates from.
Quad machines are very rare and require a stream of compressed air to play tapes back. There are only a handful surviving in the UK. Few specially trained engineers are capable of fixing them, and parts are now only serviced in the US at a high cost. Early examples of this technology are displayed at The National Science and Media Museum in Bradford (UK). It is well worth a visit.
The 1″ Type C tape
In 1978 came the format that would replace 2″ tape: the 1″ Type C tape, thinner by 1 inch, lighter, and (currently) with less playback issues than its predecessor. While quad tapes played through quadrature scanning, 1” tapes used a helical scan transport. 1″ machines are more streamlined in their set-up functions and are easier for practitioners to learn and use – especially since, unlike quad machines, they allow for video images to be seen during rewind, fast forward and different playback speeds.
This format was used from 1978 into the 1990s, with other open-reel and cassette formats being introduced in the meantime, such as ¾” Umatic, ¾” Umatic SP, Betamax, VHS, S-VHS, Betacam, Betacam SP, Video 8, Hi-8, D2 and D3. More information on all these formats can be found on the Video Identification and Assessment Guide by the Texas Commission on the Arts.
Today we only need to click to play a video or speak to tell the TV to turn on. Going back in time and spending hours with obsolete television technology is as rewarding and didactic as it is challenging, and also arguably looks more interesting than video set-ups today.
In the 1970s, prominent TV critic Clive James commented, ‘Just the colours are enchanting: there is one kind of wave-form display, expressing the picture information as a curve of light, which is the delicious green of emerald juice. The whole deal is a treat for the eyes: Science Fiction City!’
Delicious emerald juice in action.
Kristina Tarasova is a moving image archivist working in the Curatorial department at the BFI. She edits the film website Reeling The Real, and her current interests include video essays, fair use, and machinima.
Twitter: @KrisTarasova
Photo credit: Kristina Tarasova
0 Comments