|James Stewart in Rear Window|
Robert writes an occasional column, "Yellow Layer Failure, Vinegar Syndrome and Miscellaneous Musings," at TheDigitalBits.com. It's a hoot and a half.
Robert adores DVDs and home video in general for providing movie studios with money incentives to retrieve older movies from the dustbin, restore them to as near pristine form as possible, and issue them on plastic discs which will forever inveigle new generations of film buffs in their homes.
Reading through Robert's column archive is an education in itself. Before I started reading him, I was (vaguely) aware that really old films, mostly silents, were falling by the wayside due to nitrate-based film stocks which (who knew, way back then?) decompose over time.
But for most of the post-silent era, acetate-based "safety" stocks were used whose chemistry doesn't turn them into goop with time, heat, and humidity. So I assumed that just about every film I'd ever seen and loved in my post-1947 tenure on this earth was safe, right?
Wrong, celluloid breath!
The films of my youth are, albeit for different reasons, in as much danger as the cinematic contemporaries of The Perils of Pauline.
For one thing, apparently the switchover to safety film didn't begin until 1950. All the films of Hollywood's "Golden Age" were on nitrate, including such movies in glorious three-strip Technicolor as Gone With the Wind and The Wizard of Oz (both 1939).
Three-strip Technicolor? Its cameras made three separate negatives, with light passing through multiple optical pathways and filters, to represent each of the three "subtractive" color primaries: cyan, yellow, and magenta. Then each color's negative was transferred to a separate black-and-white "matrix," which was then bathed in dye of an appropriate hue and pressed against an originally clear, colorless print film. The dye thereby transferred permanently to the print, after which the process was repeated for the other two colors. At the end, the print film bore all three separate color "records" superimposed atop one another in perfect registration.
For restorationists like Robert Harris, classic three-strip Technicolor films can be a challenge. You can't simply take an existing Technicolor release print, assuming it's in the best possible shape, and copy it onto another piece of film or transfer it to video. It's too contrasty to copy or transfer properly.
So you have to go back at least to the black-and-white matrices, or, better still, to the original camera negatives, if they can be found. (I'm not clear on whether the matrices used in Technicolor restorations need to be ones that were never subjected to the dye imbibition process I just described.)
Modern color print film doesn't do things the way three-strip Technicolor did. Instead, since it uses so-called "monopack" film, it bears three layers of emulsion, one for each subtractive primary. This is the so-called Eastmancolor system, and it's been around (using a succession of types of Kodak film stock over the years) since the early 1950s.
But the Eastmancolor system presents its own problems to the restorationist. Some of the film stocks from the late 1950s, for instance, have been prone to "yellow layer failure" in which the yellow record on the print fades, leaving magenta and cyan to render distorted hue combinations when the print is projected.
A potential workaround is to locate "separation masters" made at the time the film was produced on fine-grain, low-contrast positive black-and-white film stock. One fine-grain "sep master," or just "sep," would often be made for each color record, using appropriate filters. (For example, I'm guessing — since colors on negative film are the complements of the colors in a scene — a green filter would be used to make a record on black-and-white film of the magenta record on the original camera negative.)
Making sep masters was a nod to archival needs, since they played no real role in producing the actual release prints. If seps were made at all, they were often not checked to see if they were made properly. Even if they were, years of uncertain storage conditions may have caused differential shrinkage of the celluloid, meaning the three seps no longer superimpose to make one image. The list of potential woes for the restorationist is a long one ...
Of course, the most basic woe is the inablity to find any usable "elements" — pieces of film — for entire movies or portions thereof. A lot of films or scenes have simply disappeared, or so it's seemed until troves of cinema's past glory have from time to time been rediscovered collecting dust in some collector's attic or misfiled in some musty film archive. That's when restoration wizards like Robert Harris and James Katz can really swing into action.
One of the primary reasons usable elements are hard to find for the early widescreen epics Robert Harris specializes in is that, in those days, release prints to be used in movie theaters were direct copies of the cut-and-assembled camera negative. To make each new print, the negative had to be reused to make "contact print" after contact print ... which was hell on the negative. Eventually it got so scratched and worn, not to mention dirty and falling apart due to failed editing splices, that it became useless.
Later on, the practice of making a small number of "interpositives," from each of which a manageable number of "internegatives" were generated, arose. The internegatives were then used to make the release prints, a procedure which preserved the camera negative for posterity.
Another problem plaguing the restorationist's task is "vinegar syndrome," the tendency of chemical reactions in so-called safety film stock's base to gradually and unstoppably ruin the film element by turning the cellulose triacetate in the base to acetic acid, the essence of vinegar. In older 35mm prints using the four-track stereo soundtrack popular in the 1950s, the magnetic stripe used for the additional sound channels even acts as a catalyst in accelerating the vinegar syndrome. Jeepers!
Harris' column is about more than just film restoring, by the way. It's really about the love he has, and we all should have, for the history of the silver screen. Thanks to DVDs, and to laserdiscs before them, and now to high-definition video, that history and that glory is not likely to fade out, ever, as Harris is continually pointing out. As long as money can be made resurrecting the treasures of the past and putting them out on home video, Hollywood will not let (say) the stunning dance routines of Fred Astaire and Ginger Rogers die. (Many of their movies from the 1930s are due on DVD soon.)
So, each time a nugget of ancient or not-so-ancient movie gold reaches DVD, Robert is apt to highhlight it in his column. Those who are interested in film classics but don't particularly care about the travails of restoring them will find Robert's words fun reads, even so.
You can read more about Robert A. Harris and James Katz in "Robert A. Harris: Tilting at Hollywood" here. The Rear Window project is documented here.