If tape is dead, why are so many new videotape formats being introduced? Recently, Sony came up with HDCAM SR (and an even higher data-rate variant) and MicroMV. JVC was the first of several manufacturers to show a version of the MiniDV cassette-based HDV format. Panasonic introduced a form of 625-line D-5 incompatible with previous versions as well as the narrow-track-pitch DVCPROHD-LP.
The bigger news this year, of course, was the introduction of new tapeless video recording formats: Sony's blue-laser disk-based camcorder, Panasonic's solid-state camcorder, and JVC's magnetic disk-based camcorder. They joined existing disk-based camcorders from Hitachi and NEC and magnetic disk camcorders from Ikegami. As for the solid-state camcorder, Panasonic was able to demonstrate its not-yet-extant professional version with a consumer camcorder using SD memory cards.
All of the tapeless camcorders promise advantages in almost every aspect of television recording. They allow instant access to any moment on a recording and, therefore, nonlinear editing with no need for a loading step. They allow "loop recording," the ability to press record after the desired moment and still capture it. In some cases, they even offer smaller camcorders and recording media.
There's only one aspect of television storage for which the new systems are--at least at the momentÑscary. That's archiving. How much will it cost to archive the new media, and will they be playable in the future?
The cost issue is most apparent in the solid-state system. If the current pricing structure for SD memory (including discounts for larger sizes) applies to the new cards, then a 4GB card (18 minutes of DV quality, 9 minutes of 4:2:2 DVCPRO50 quality, or 4.5 minutes of HDTV as recorded on DVCPROHD) would cost about $885. If the cards were to be archived directly, each hour of HDTV would cost about $12,000.
Not even Panasonic recommends that. After editing, material would be transferred to an archiving medium. But what should be transferred? It's no big deal to record a tape copy at the same time that a nonlinear editing system plays an edited sequence. It's more time consuming to transfer all of the original camcorder footage.
Then there's the question of what medium to use for archiving. Sony's blue-laser disks are relatively inexpensive, but it's too soon to say how long they'll last. Panasonic's cards will cost more than tape, but they'll also take up less room, offering savings in real estate. NBC once threw out a huge archive of videotapes because it was taking up too much room.
In theory, the answer shouldn't matter. Bits are bits, and one advantage of digital recording is that an unlimited number of clone generations--in any format--can be created with no degradation. Practice is something else.
The first nonlinear television editing system to be sold, the CMX 600, used disk drives the size of dishwashers, and disk packs the size of large layer cakes. It's a common saying that as soon as one buys a computer, it's already obsolete. Data storage technologies change rapidly.
The root of the word "digital" is the Latin digitus--a finger or toe. In that sense, the first digital recordings might have been the finger-painted cave-wall illustrations that have remained intact for many millennia.
Kodak, perhaps as part of its goal to redefine itself as a digital imaging company, recently announced a decision to phase out slide projectors. That's an image-display technology that has been around at least since the 17th century.
Curiously enough, it also happens to be a digital image-display mechanism, and not because slides are placed into trays with fingers. It's digital in the modern sense of something dealing with only two states: on or off.
The photosensitive grains in film can be either exposed or unexposed. There's no in between. Different grain sizes require different amounts of light for exposure, providing shades of gray, but each grain is a strictly digital light sensor.
Archivists often debate the lifetimes of different digital storage media, but one always seems to outrank the rest. To be certain of both durability and compatible playback equipment availability, use film.
Mark Schubin is an engineering consultant with a diverse range of clients, from the Metropolitan Opera to Sesame Workshop.
