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The Auto Conform Process

The Agony and the Ecstacy By Steve Wright

The Digital Intermediate (DI) process required the introduction of computers into the color timing of a feature film. That was the point. The fact that the entire feature film was now being digitized, manipulated, and color timed on a computer also opened the door to a whole new option - auto conforming the film. While a glittering business opportunity for all parties, the agony of auto conforming for the DI studio is a painful increase in the complexity of doing the job, while the ecstasy for the client is the many marvelous benefits. When deciding whether to go for the auto conform process or the more traditional conformed negative process, the savvy client will want to know the payoff and pain of each option.

One of the essential steps in making a feature film is "conforming", the process of cutting the selected shots out of the original camera negatives and splicing them together to create the final edited version of the movie.  Before computers were introduced to the editing process this was done by making a projectable print from the camera negative (called "dailies" or "rushes") then cutting the selected scenes out of these prints and splicing them together to make an edited version of the movie. After many iterations, the edits were finalized (i.e. the picture is "locked" ) then the precious, irreplaceable camera negative was cut by negative cutters and spliced together so that the original negative "conformed" to the version made by splicing the prints together. This conformed negative was then taken to a film lab for color timing using the "wet" process of chemicals and exposure lights.


Starting in 1989 the editing process for movies became computerized with the introduction of the Avid editing system. The film is first transferred to video, then digitized into the computer where all of the scenes can be randomly accessed by the editor. The movie is edited in video so that the edits can be revised in seconds and the new version viewed instantly on a TV monitor -  a vast improvement over cutting up prints, splicing them together, then running off to view the new version in a screening room. Once the picture is locked, the Avid can print out a list of the camera rolls and keycodes from the original camera negative that was used to make the video version. This list is then given to a negative cutter who cuts up the precious and irreplaceable camera negative and splices it together to conform it to the Avid editing list. This conformed negative is then taken to a film lab for color timing using the wet process.


While we had computerized the decision making process of editing a film, the physical editing of the negative into a conformed reel remained unchanged from the last 100 years of filmmaking.


Fast forward to the year 2000 when the Digital Intermediate process was introduced.


Now the entire feature film could be digitized and color timed in a computer, a vast improvement in creative control and accuracy compared to color timing in a lab. However, the movie was still being conformed by cutting up the precious and irreplaceable camera negative and splicing it together. In fact, the exact same conformed camera rolls were delivered to the Digital Intermediate studio that would have been delivered to the lab for conventional color timing using the wet process.


The Ecstasy

Today, however, a dazzling new option is becoming available to the filmmaker, the "auto conform" process. Instead of delivering a conformed negative to the DI studio, all of the original uncut camera rolls can be delivered along with a computer generated assemble list. The final movie is then conformed automatically, or "auto conformed", by the DI computer. This electronically conformed version of the movie is then color timed and output to film without cutting up the precious and irreplaceable camera negative. Not only that, last minute changes become simple - just scan the newly selected scene and digitally drop it into the movie. There is also the added bonus that the camera negative is left totally pristine and uncut for any future repurposing.


The Agony

As wonderful as the auto conform process is for the client, it is equally agonizing for the DI studio to provide because it dramatically raises the complexity and difficulty of delivering a Digital Intermediate. With the conformed negative approach all that the client delivered to the DI studio was the 10 to 12 one thousand foot rolls of conformed negative. Each 1000 foot roll was placed on the film scanner, the scanner operator punched "go" and headed for the cappuccino machine while the scanner ran for 12 hours or so before the next reel was loaded. When the negative scanning was done, all you had to do was drop in the digital effects shots and titles and conform them by hand. Since there were typically only a few dozen of these shots, it was no big deal.


With the auto conform process, all of the original camera rolls that had any scenes used in the movie have to be delivered. This is typically 400 or 500 camera rolls. A bit of a shipping, inventory, storage, and liability problem, but manageable. But now we can't just mount a 1000 foot reel on the scanner and walk away. Each of the 400 or 500 camera rolls has to be scanned - after it has been ultrasonically cleaned, of course. There might be from one to ten selects to scan from a given camera roll, so somehow the scanner must be told exactly where to start, how many frames to scan, then where to go to get the next shot. The scanner must "fast forward" to the next shot, and while it is fast forwarding it is not scanning, and when it is not scanning it is not making money.


Not only do we now have to scan all the little bits from each of 400 or 500 camera rolls, each frame must be appropriately named or numbered to identify exactly where it came from so later it can be electronically conformed. With the conformed negative method all the frames were already in place and in the right order. They could simply be numbered from 1 to 16,000 or so (16 frames per foot for 1000 feet) at scanning time and color timed. The auto conform process requires each frame to be properly identified so that it can be fetched later and dropped into its proper location in the reel by the computer.


It would be beyond risky to ask a frail and fumbling human to manually type the thousands of scanning commands that are needed for a feature film when a single typo could introduce a schedule crushing delay. No, we need a highly reliable computer program than can generate a frame accurate scanning script to control the film scanner automatically. The camera roll is placed on the scanner and the appropriate scanning script is called up, and now the scanning operator can head for the cappuccino machine - but wait! The scanner now finishes in just a few minutes because we were only scanning a few hundred frames from a camera roll. Got to reload another camera roll and start another script. Oops, scanner #2 just finished its camera roll and now it needs to be reloaded too. We are going to need more people to run the scanners, because this is no longer a "set it and forget it" operation.


Accurate scanning scripts are obviously critical for an efficient and error-free film scanning operation, so what information will we need from the film's editorial department to create the scanning scripts? Well, let's see now. . . we will need to start with an assemble list so we know the order to place all the pieces of film and where each piece comes from. We will also need a pull list because it lists which cuts to use out of each camera roll. We need this information so that we can put up a camera roll and scan all the shots that come from it regardless of where they appear in the film to avoid reloading a camera roll multiple times for each shot we need to scan. Of course, we will also need an optical pull list so that we will know what frames to scan for the opticals and titles.


We will also have to smarten up our script generating program to spot any re-use of a cut so that we don't mindlessly scan the same cut twice. While we are at it, we might as well add enough smarts so that if two cuts overlap each other the computer can recognize that fact and figure out the first frame of the first cut and the last frame of the last cut, and then scan the frames for both scenes as one continuous scan.


One of the problems with all of these lists provided by the film's editorial department  is that they are not standardized yet. You need another computer program that can take in various versions of these various lists and parse (pull out) the essential information without getting confused. Conceptually trivial, but maddeningly complex to implement on a computer. Add to this that each client seems to be using a different version of software that produces a different version of these lists, plus there are operator selected options for creating these lists which seem to be set differently each time they are generated. All of this adds up to a confusing array of different list formats even from the same client that is sure to crash any parsing program. 


We are also going to need the CMX3600 EDL, of course, since this is the editor's actual Edit Decision List describing exactly how the movie is to be cut together - in video.  While the assemble lists and pull lists are used to tell the scanners what frames of film to scan, the EDL is what tells the computer how to conform the finished movie. Tragically, the Avid was given video tapes of all the camera rolls so the entire movie was edited in video. This means that it provides video timecode for the source of a shot and video timecode for its destination on the finished video tape. The assemble list and pull list described above are in film frames, but the EDL is in video timecode.


Not to worry.  Our very modern and powerful computer can automatically convert video timecode into film frames. We just have to tell the computer whether the EDL is in 24 frames per second or 30 frames per second format. Did the editor set the job up as a 24fps project or a 30fps project? If it was set up as a 30fps project did the editor convert it to 24fps when printed out for us? It's just one more little layer of complexity that we will have to sort out before we can auto conform the movie. The obvious lesson here is for the editorial departments of the feature film and the DI studio to be in very close communication. 


Remember one of those fabulous features of the auto conform process was how editorial changes are now trivial? The problem is, since they can be done, they will be done - by the bushel! In the past you simply could not change your mind after the negative was conformed because the camera negatives had been all cut up. Not true anymore. With the auto conform process the electronic editing can be revised in perpetuity with impunity (save the impact on schedule and budget). Unfortunately, it also panders to the indecisive waffler. Obviously, this situation can easily get out of hand and provides yet another fine example of Wright's Paradigm: "Creativity will always expand to fill the technology."


The root cause of all of this agony in the auto conform process, is, of course, the lack of standards in the industry for passing editorial information to the DI studio. Until this issue is addressed, the auto conform process will remain painful. Conceptually, auto conforming is exactly the type of problem that the computers that are already used for DI can handle easily. Their mindless accuracy and inexhaustible thoroughness make them the perfect tool for flawlessly conforming the roughly 2000 shots and 180,000 frames of a feature film. When appropriate standards and practices are finally settled in the rapidly evolving Digital Intermediate business, the auto conform process will become the defacto standard in the industry.

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With nearly 20 years of experience in CGI and digital effects, Steve Wright is also an international speaker, published author, and widely recognized expert in the digital effects industry.

Steve is an industry veteran with in-depth production experience in digital effects and CGI for feature films and broadcast television commercials, as well as feature film Digital Intermediate. As Technical Director and Senior Compositor for Kodak's Cinesite, he has created digital effects shots for a long list of top Hollywood films. His earlier production experience includes eight years experience as an in-house digital effects producer and  supervisor for CGI studios. He is highly experienced with client interface, storyboard breakdown, production bid preparation, and project management and has extensive technical and artistic experience with digital effects, 3D  computer animation, and even digital ink and paint for cel animation. His production experience includes three years as a 3D animator and 12 years experience of compositing and digital effects. His production projects include over 40 feature films and over 70 broadcast television commercials plus numerous special venue projects. His many feature film credits are listed on IMDb.

To contact Steve or see more of his production background visit his personal web site at Click on the book cover to below to see Steve's very popular book on Digital Compositing.

Related Keywords:auto conform, cut negative, conformed negative, digital intermediate, conforming, assemble list, pull list, optical pull list, DI,


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