Archiving video on film as _digital_ data?
Posted 19 June 2005 - 10:55 AM
I suppose the advantage of this approach would be the long, proven "lifespan" of film stock compared to magnetic or optical digital media. If a digital pattern of data were recorded optically into film stock, future generations of engineers could invent new mechanisms to "read" the data, even if the original machines became worn-out or lost.
I'm guessing the digital data would be "scribed" onto film using a laser, perhaps mounted in a helical drum assembly, similar to the way today's magnetic video head assemblies work?
Anyway, my apologies if this is old news (and is already in everyday use) or has been discussed previously -- but if not, I'm just curious if this idea has any merit.
All the best,
- Peter DeCrescenzo
Posted 19 June 2005 - 04:00 PM
I don't think it's a new idea, but yeah, sounds reasonable. If bloody expensive; it'd have all the downsides of both formats as well as their upsides.
Also, this "film as an archival medium" propaganda isn't entirely accurate; film only lasts more than a few decades if it is stored extremely carefully. I'm sure it'd be possible to make a CD-ROM or similar optical disc last just as long if you didn't let the metal layer corrode.
Posted 20 June 2005 - 02:24 PM
Columns of Data: 180
Rows of data per second: 32,494
Track Width 0.102 in (2.59 mm)
Bit size, 35mm (height x width) 14 x 14 microns (0.00055 x 0.00055 in.)
Bit size, 70 mm (height x width) 17.5 x 14 microns (0.00069 x 0.00055 in.)
At present, digital masters (Digital Intermediates) of feature films are recorded out to film, either as a master positive or duplicate negatives (often on very stable polyester base). Long term preservation strategy usually included storing these color elements in cold and dry storage conditions recommended for long term storage (SMPTE Recommended Practice RP131), and making and "proofing" B&W silver image separations stored in a separate long term storage vault.
There are many nitrate films well over 50 years old that are still in very good condition. Polyester film base has a very good record of keeping stability, based on widescale use for almost 50 years.