Digital vs. film preservation (was: AMC "Film Preservation Festival"?)

From: David P. Hayes
Newsgroups: rec.arts.movies.past-films,
Date: Thursday, June 11, 1998 8:37 AM

David Mullen <ERICUSC@UCLA.EDU> on June 7 began by quoting me in message<ERICUSC.1037.0008EE37@UCLA.EDU …>:
>>Going a little off-topic: I've written before of my belief that preservation
>>efforts are misguided inasmuch as they strive to make new copies on acetate
>>film when instead a high-resolution digital medium would offer more
>>durability, more fidelity and less cost.
>We've had this discussion before -

Okay, he's familiar with the previous posts.

David Mullen<ERICUSC@UCLA.EDU> wrote June 8 in message<ERICUSC.1040.000F1746@UCLA.EDU …>
>I'm still unclear as to what digital format and resolution you are referring
>to when you say that digital storage is cheaper, etc.

When I wrote on this Jan. 13, I discussed that "the square of each pixel is [to be] duplicated in the same position on the receiving [digital] media." This should make clear that I am discussing a means of reproducing every bit of detail. I added that time that film stock could not be relied upon to deliver every bit of detail unless the receiving film stock was of such fine grain that there wouldn't be the concern about grains from the original image "bleeding" across several grains of the copy. As I stated then:

"The individual grains of light-sensitive 'dots' on film stock are invisible to the operator engaged in copying from another piece of film or from a video source; the grain positions have to be unknown until film stock has left its dark enclave and has been processed, and then it's too late. If an operator can't manipulate film stock so that there's 1:1 correspondence of digital pixel to film grain, then it becomes compelling to increase the incidence of digital pixels so that when each film grain is hit with digital beams, it receives such an excessively detailed image that the average hue of the squares that becomes blurred onto that grain will better represent the video source.

"(It doesn't help that the film grains are not in the same position from one film frame to the next. The manufacturing process can't guarantee that. Digital video gives each pixel an 'address' that places it at a screen location that remain fixed from one frame to the next.)"

A new observation:

The $50 JPEG programs sold for Windows 95 and often found for free on new computers, permit users to customize the number of resolution dots of the horizontal and vertical axes. Why wouldn't it be obvious that on professional programs costing thousands of dollars and intended for important work, that they too would enable as much resolution as needed?

>"Snow White" cost
>something like 2 to 3 million dollars to restore digitally. For "Vertigo",
>digital restoration of a few scenes was outside its budget. So how can you
>say that digital preservation is cheaper?

In the first two sentences of David Mullen's quoted above, he speaks of "restoration." In the last sentence, he writes of "preservation." The two words do not mean the same thing. The expenses of restoring -- of fixing the ravages of time -- are a whole additional burden beyond that of relatively-simple reproduction.

In my Jan. 13 post, I wrote:

"Sony's restoration on digital video of "The Matinee Idol" was… intended as a demonstration of what digital video was capable of accomplishing, from a technical standpoint. Scratches were removed, missing emulsion was replaced from adjacent frames, deterioration was covered up. A tremendous amount of human labor went into these tasks."

These (optional) tasks are where you have the expense.

>So please specify the parameters of this digital preservation system that you
>are advocating. And does it include the costs of making 35mm prints for

As I wrote Jan. 13:

"Sometimes the argument is raised that projection copies will still be needed on 35mm. Such a view doesn't consider the development of video-projection devises that have or will have the resolution and color/hue range of film; such machines might be expensive, but could be paid for relatively quickly with the savings from not making new film prints. One should also remember that a typical obscure film once preserved may be seen on film by only a few hundred people, excluding people who'll see it only on video; the cost of a film print divided by the number of people who would see the print, results in a substantial subsidy per person. Such dollar amounts may not be discussed openly, but they will be a consideration for any preservation undertaking, private or public."

>the cost
>of making a 35mm print from a digtal HDTV source is something like $60,000 (at
>Sony Hi-Def center) which is a lot more expensive than a normal 35mm print
>- PLUS will not look as good.

In answer to the objection that a digital video presentation won't look as good, I wrote on Jan. 16:

"Theoretically, there is no limit to the number of colors and hues possible by forever increasing the number of bits per byte, but in actual practice, we must remember that film itself does not completely accurately reproduce the colors and hues on the source material. There is always a tolerance level. Once we determine what that level is for film, we can apply the same numbers for video. The programmers can always opt for a higher standard for video, but for purposes of cost comparison, it is only fair to determine the financial outlay for the same degree of quality."

Mullen might have been concerned about a loss of quality suffered by the 35mm print copied from HDTV (or higher-resolution digital video method), where on the film print failed to capture the full sharpness and/or color/gray scale as the digital source. If this is the case, there is another reason to project directly from digital video equipment in the auditorium.

>It seems to me that assuming that Disney kept any digital data files for the
>"Snow White" restoration, if in fifty years, somebody opens a vault and
>finds (1) the three b&w negatives, (2) the color I.P. from the restoration,
>(3) any dye transfer and EK prints, and (4) some sort of data files containing
>the digital version of the movie - they are most likely to use the data files
>LAST since they won't have a computer or any machine to look at them on.

The three black & white negatives are likely to have shrunk at different ratios from one another. Inconsistent shrinkage has been the bane of restoring color films.

>What would a movie be stored on: CD's? Digital magnetic tape? We have some
>pieces of film that are 100 years old and are still playable

What percentage of film 100 years (and intended to be kept) has survived? The history of film archiving is one of dedicated people going into a vault and finding that stored film has decomposed (or worse). Lois Weber donated her films to the Academy of Motion Pictures Arts & Sciences. They all rotted there.

Other than in this sentence, I won't address the film prints that spontaneously combusted and took with them the adjacently-stored reels that burned to a powder.

- when we have a
>CD that is that old and is still playable, THEN maybe we could trust it as
>as long-term storage format…

When digital media is suspect, it can be copied by a dolt to new media.

>In my opinion, digital storage of motion picture history could well
>mean the loss of such history, not the saving of it. I mean, isn't it the
>opinion of the Library of Congress that film is still the best and
>longest-lasting medium for storage of motion pictures? Did they just make
>that up are do you think they did some research first?

I realize that the L.O.C. studied the matter and continues to do so. Then again, since when have government agencies (or private bureaucracies) adapted new methods before it had become a public embarrassment that they continue to use outmoded ones?

David Hayes


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