Film archivability - color loss
Posted 07 December 2010 - 09:27 AM
I prefer to shoot film and have my own S-16 gear. Much of what I am shooting now (docs and sponsored industrial) is on XDCam but film is still my first choice because I like the look and I think it is the most secure medium for preservation of historically important subjects.
However,I recently sent an answer print of one of my projects from the '70's to transfer. Original footage would have been reversal Kodak stocks. The lab examined the film and reported that in many scenes the fading was so severe that only the magenta layer seemed intact. Yet other scenes looked almost normal. I am going to go ahead with the transfer and see what my editor can fix but I wonder why the variability and is this generally the fate of most films this old?
If I store today's project on a hard drive or optical discs will they even be watchable in 28 years?
Posted 07 December 2010 - 09:49 AM
Posted 07 December 2010 - 10:24 AM
As far as a heavy Cyan print or reversal stock goes I have been able to digitally restore films with this problem by doing a data scan (2K) and then using curves in Color or Resolve. The key to this is the RGB scan where each color is a individual channel (instead of video YUV) and the fact that the scan process does not add any significant noise. The end result of manipulating each channel individually with curves can be stunning.
So form my experience film lasts very well and can be resurrected if it has problems even almost 100 years later.
Here is a pic from a 1929 35mm Nitrate film from this week at Cinelab, the smiling guy is a forgotten US vice president.
Posted 07 December 2010 - 11:13 AM
I'm not sure about VNF-1 or ECO, but I know other reversal processes relied heavily on a color stabilizing agent and proper wash time. If the stabilizer were exhausted, this would have the effect of severely reducing the stability of color dyes.
There's an excellent (though dated) book on the subject, worth owning in print, but available for free online. . .
This is the chapter I believe would best answer your questions.
Unfortunately, WIR seem to have concentrated entirely on consumer (digital) imaging now, and only still photography. The only silver halide materials mentioned in their current publications seem to be 4x6" paper from 1-hour photofinishers. There isn't a single mention of a modern film. I can only assume there have been improvements across the board by manufacturers.
One anecdotal piece of information: Based on what I've seen, Fuji products tend to last TWICE AS LONG before fading as Kodak, for most color products. That was roughly true of all the negative films, print films, reversal films, and photographic papers except now defunct Kodachrome products.
Kodak only made improvements in its Ektachrome line (and then, not with VNF films). I would assume the current E100D stock has much better stability than VNF did, but doubt it has the archival properties of Kodachrome.
Posted 07 December 2010 - 11:23 AM
Most labs try to retain tight control on color developer
activity — that is, to reduce any process deviation result-
ing in image-quality losses that can be visually assessed
immediately after processing. But other processing prob-
lems, such as too-diluted (or omitted) C-41 or E-6 stabilizer
baths, excess bleach-fix carryover, or inadequate washing,
may not manifest themselves until months or years later.
The photograph studio at the Metropolitan Museum of
Art in New York City discovered rapid and irregular ma-
genta dye fading in a large number of Ektachrome trans-
parencies processed by an outside lab in New York be-
tween 1982 and 1987.21 The transparencies, most of which
were in the 8x10-inch format, were of paintings, sculptures,
and other artifacts in the museum’s collections and had
looked perfect when they were received from the lab. (The
Metropolitan’s photograph studio is a large operation that
produces between 3,000 and 5,000 large-format color trans-
parencies a year.) Many other Ektachromes from the same
period have not faded prematurely, and none processed
before 1982 exhibit the problem; all were stored in the dark
under the same conditions.
After investigation, the cause of the premature and ir-
regular fading and streaking was attributed to low solution
level in the E-6 stabilizer tank in the processor or, possibly
in some cases, omission of the stabilizer altogether.