This article appears in the July Issue 1, Volume 4 of DigitalCinema Magazine
This article appears in the July Issue 1, Volume 4 of DigitalCinema Magazine
There's an old poem about five blind men who stumble up against an elephant in the jungle. As they feel about on the particular section they've each stumbled into, they draw conclusions about the beast's design. The man who is feeling the elephant's ear is certain that it is a huge, flying, bat-like creature while the man who fell upon the leg visualizes it as a mighty tree. The guy at the back who is holding the tail is sure it is built like a vine while the two guys in the front with the trunk and tusk argue wether the elephant is more like a snake or a spear. The poem concludes something like ... they argued on into the night, with reasons short and long, while all five men were partly right, they all were very wrong.
I often think of that poem when someone starts pontificating about their particular take on Hi Definition. To be fair, they are usually correct within a limited context because HD is such a hulking pachyderm and it all depends on what part of this industry you've bumped up against it from. Are you a production person who's concerns are shaped by the price/performance ratio? Are you a postproduction person who is faced with a myriad of resolution, color-space and I/O issues, or do you deal more with the distribution, technical, sociopolitical and economic factors involved?
Anyone with above room temperature IQ will realize that HD (or its next of kin) will eventually replace film. Maybe not next week, or even next year, but someday soon. It's almost like the hype we were fed by over zealous journalists when they predicted that computers would usher in the age of the "Paperless Office." The makers of celluloid, like the makers of paper can sleep soundly for a bit longer.
In the first volley of this three part series we'll intentionally start in the area that uses far more HD than any other, postproduction.
THE POSTPRODUCTION FLAVORS OF HD
Whether you're shooting a commercial, music video, documentary, episodic or full blown cinematic venture; if you've got a substantial number of visual effects, you'd be hard pressed to find a better production format than HD.
With film acquired projects, the ability to create effects within a cross industry standard format gives you the ability to weave elements from a wide variety of sources into the final movie. When using HD as the main acquisition medium, the ability to create effects within the native format more than makes up for the compromised resolution and colorspace. There are of course a lot of different kinds of HD, and like the blind men and the elephant, everyone has their own take on the beast.
Please keep in mind that HD isn't new. The No-Holds-Barred, Last-Man-Standing, Smack down of HD standards has been raging for more than a quarter-centruy. Here then are my own favorite flavors of HD.
SHOOT ON FILM > SCAN TO HD DATA FILE
The use of the HD format for motion picture applications isn't really all that new. Back in 1993 we were ask to add some visual effects to a movie that had tested quite poorly. One of the movie's producers had seen a technology demonstration that I'd given a few months earlier at the Director's Guild of America where 35mm film had been scanned to 1080 HD aspect, imported into a Macintosh computer, and then printed back out to film.
You know the old saying about "PRICE, QUALITY or SPEED. Pick any Two"? Well these guys wanted PRICE and SPEED and we all agreed that the methodology seemed appropriate. We shot and created a series of seven visual effects for their movie about a genetically engineered dog that runs amok. 'Man's Best Friend' screened a few weeks later and tested much higher than before. The studio released it and that was pretty much the beginning of a long and profitable carrier of creating last minute effects and repairs to motion pictures.
Even though it would be a good decade until video manufacturers would actually deliver a reliable 24P HD recording system, a number of forward thinking software companies had already included HD as a native format in their motion graphic applications. Most notably was a small group of engineers who called themselves the Company Of Science and Art. A year or two later, Adobe acquired the relatively obscure COSA AfterEffects and the rest is, as they say, history.
Of course back then the process of moving HD around the desktop was unmercifully slow by contemporary standards, but it offered a methodology that was soon to become universally accepted.
A few years and a half dozen movies later, Fox Studios realized that they just didn't like a number of effects that they had received for their MIGHTY MORPHING POWER RANGERS movie and hired me to re-do several of the main morph sequences. Given the choice of "PRICE, QUALITY or SPEED, pick any two" Fox Studios chose SPEED and QUALITY so we scanned the film elements to 1920 X 1080 24P data files in 12bit .sgi format.
By this time up conversion algorithms and tools available on the desktop had matured significantly. Thanks to the enhanced speed of the early Macintosh Quadra computers and an early prototype HD VideoExplorer video graphic board, the job was delivered three days ahead of schedule.
Even though the actual HD cameras were still analogue back then, the inherent methodology of scanning film to HD aspect at 12bit colorspace data files has proved to be an efficient production methodology and still represents the highest quality flavor of HD.
SHOOT ON FILM > TELECINE TO HD DATA FILE
Four of the last half dozen motion pictures that I've used HD on have been shot on conventional 35mm film. Rather than paying a buck or two a frame to have all of the various effect sequence elements scanned, they were telecinied in real time at 2K on a Spirit DataCine, and then transferred to FireWire Drives in 10 bit .sgi file format. Since the HD data stream was never subjected to the forced compression and down sample of the 3:1:1 HDCAM video format, the resultant images were far more robust, with much greater colorspace. Having never touched video tape, this flavor of HD is a pure data format and represents what is perhaps the most popular of the postproduction HD flavors.
Since the 6MB frames are stored as 10bit .sgi files, you can import them directly into your Flame or Inferno workstation without any transposition whatsoever. The important thing to remember here is that the vast majority of professional colorists have a 'look' that they've built their careers around. Whether using their 'look' or the 'House Look' is almost always predicated on a telecine setting that is intended for broadcast applications. The gamma, histogram, colorspace and actual transposition scheme that you use to transpose the 35mm image into a HD file for printing back to film are completely different.
After using nearly every telecine in Los Angeles, it has become rather obvious that the machine isn't nearly as important as the operator. Tony DiAmore, a Colorist at the Hollywood based Encore, has a ring side view of HD's transition into cinema. "The most important thing to focus on, and I can't really stress this enough, is to get across the fact that you don't want 3:2 pull down" Tony says as he pulls a bit of reflected blue out of the skin tones. "One frame of film needs to transpose to one frame of HD. No more, no less. If you miss stressing this very vital bit of information up front when you're ordering the job, you'll just end up buying yourself another telecine session".
Even though you might be at a major facility, and the colorist and your account executive all have years of experience in the business, this could very well be their first experience with cinematic HD. You'd better have your act very solidly together before entering this arena.
The most recient film that we've used this methodology on was David Lynch's soon to be released MULHOLLAND DRIVE. Having served as DP and Visual Effects Supervisor on a prior job with him, I was becoming familiar with his color pallet and density preferences. Rather than waste bandpass by timing the elements after they were on the desk top, we timed the sequences while they were still in the virtually unlimited analogue world of film. Timing at transfer is quite similar to timing HD in the field. By getting the signal profile closer to the desired print envelope you essentially gain upwards of 30% more usable resolution.
Phil Azenzer, Encore's most seasoned Colorist adds, "When we were transferring the visual effects elements for MULHOLLAND DRIVE, we used a series of histogram based presets that were quite different from the industry standard broadcast settings. Rather than just timing for the average center line, we wanted to get more development from the shadows and muted tones that actually comprised Mister Lynch's shots. The results were quite spectacular."
The absolute best strategy for success is to do a short test, transfer it to your workstation and then print it to film. It either works, or it doesn't and you'll go into the rest of the project with a far more secure feeling. To quote my good friend Sean Fairburn SOC, "A test not pushed to failure is quite simply not a real test."
Once the film frames have been converted to data frames, the rest of the production process is plug-and-play as the data files are effortlessly moved between platforms by the ubiquitous FireWire drives. Figure that a pocket sized 30 Gb FireWire drive can easily carry enough high quality HD elements for a half dozen effects and the unprecedented efficiency and economy of this methodology becomes readily apparent.
One of my favorite aspects of the new generation of portable IEEE-1394 drives is that since they're powered by the FireWire buss, the majority of them don't even need an external power supply.
A quick note about a very common misconception with regard to FireWire: IEEE-1394 is a data transfer specification and while fast enough to transfer a sequence of files so that they can be displayed in real time DV, IEEE-1394 is NOT a video format.
SHOOT ON FILM > TELECINE TO HD D5
Think of 24P/SF as an interlaced signal without the temporal displacement. A progressive scan HD frame in Segmented Frame mode is actually written to the tape as two separate frames which are later pieced back together by a combination of hardware and software wizardry. While the frames of both 1080i and 1080P/SF HD are composed of alternating odd and even fields, the fields in SF more closely resemble those created by a line doubler than those recorded 1/60th or 1/48th of a second later.
Once you start to mix and match analogue and digital elements you've entered into an area that requires a good deal of craft. Film and HD are entirely different beasts and just about every possible factor that you can imagine comes into play when you try to combine the two. Film has a certain quality and texture to it, a ruggedness that is inherent to the photo chemical process. HD on the other hand is a purely binary beast and differs greatly in spacial resolution, color space, depth of field and latitude. With film you're recording onto an RGB negative while HD is more like a fast color reversal stock. Then there's the all important introduction and subsequent matching of grain.
Often overlooked in the inevitable comparisons between film and HD is the basic motion of the framed image itself. While the sequential recording, duplicating and subsequent projection of film introduces a varying amount of gate weave into the film based sequence, HD is rock solid. I've shot HD in controlled environments where everyone was highly conscious of their movements and have still seen sub-pixel motion artifacts when the element was composeted to another layer of HD.
As bizarre as it may seem, the inherent resolution of today's HD cameras can pick up the heart beat of an operator sitting on the camera dolly. While this phenomena is rarely if ever witnessed in film post production where minute amounts of jitter and weave are part of the texture of the medium, the absolute steadiness of the HD image is an altogether different beast.
One of the gags for LArceny involved panning around a bullet, frozen in time, that hovered just in front of the lead's face. The bullet and subsequent wave distortions were all rather easy to create within the computer environment but the almost infinitesimal alignment of a CG element in a constantly changing spatial dimension turned out to be one of the more complex gags we've done in a while. The CG bullet slowly revolved on the Y axis and needed to match the film based physical action that also revolved around the Y but also had gate weave, operator movement, DOF shift, dolly rail hits and grain motion.
"I was a bit concerned about cutting all that HD into my 35mm film" says Irving, "but after reviewing a number of highly successful films that Scott had already used the same technique in, I decided to give it a try. I've got'a say, it all cut in seamlessly and saved a considerable amount of both time and money."
SHOOT ON HD > DIRECT TO DISK (Accom)
Nearly all of the effects for The Yellow Bird had to do with inserting a small yellow bird into the shot. Whether live action or computer generated, more than a dozen shots were composited by the students at Gnomon School of Visual Effects.
In addition to being one of the film industry's leading graphics experts and one of the directors at Gnomon, Pam Hogarth served as our CG producer on this project. "Working in HD on this movie was a great experience for our students. It not only gave them a chance to work with seasoned industry professionals, but they also got to work with numerous types of very high quality, cinematic HD. This whole industry is changing faster than it ever has. A rich and varied understanding of not just the technical aspects but also the craft of cinema is what will build successful careers."
While the CG bird was being modeled and animated in Maya, I shot several elements of a real bird flying against blue in HD which were recorded directly into an AccomHD Digital Disk Recorder (DDR). While not quite as robust a signal as the telicine from film, direct-to-disk acquisition is generally far superior to tape acquisition for motion graphic applications.
While the HDCAM image comes off the chips at 4:4:4 RGB color space, the actual HD signal is created in a 10 bit YUV color space. The system then does a "pre filtering" or down sampling from 4:2:2 (22:11:11) to 3:1:1 before applying final compression and then recording the final image onto the HDCAM tape. The trick with chroma key is to capture the signal before the down sampling, which in this case is as simple as pulling the component signal off of the three BNC connectors on the side of the camcorder.
An extra bit of colorspace can be gained by converting the signal in-line before capture from the native 10 bit YUV to an 8 bit RGB. Not only is an image stored in the RGB format more robust and rugged that its YUV equivalent, but the colors available for chroma key work are almost double.
SHOOT ON HDCAM > DESKTOP CAPTURE
"A good title sequence tells the audience that they're about to experience something new," Schwartz explains, "it gives them a preview of the production value and sets up the story."
In Irving's movie, Joshua Leonard plays a slacker who travels to LA in an attempt to help his quirky cousin (Andy Dick) fight off premonitions of death. In an attempt to endear himself with women, the young itinerant represents himself as an accomplished painter, which he's not. Since there were no pre-existing elements to work with we started from scratch with a design theme inspired by the great Saul Bass. The sequence starts with a silhouetted character that paints on the title as well as various silhouetted women who then interact with and change the credit elements.
The gag relied on pulling luma keys in post so I timed the Panavision/Sony F900 for a very thick, low contrast signal that transposed much of the chromanance into luma values. Since this wasn't a big ticket item I set my own lights, engineered the shot and served as both DP, Director, Visual Effects Supervisor, Gaffer, Grip, Best Boy and Janitor (which I have done professionally at various points in my career).
Since we were recording action and not facial expression, the lighting was relatively simple ... slash the background with a coupl'a barn'd 5Ks, cut the spill with a couple flops, throw up a 10K for fill and double down to flatten the scene.
The dancers came in (both highly trained professionals), we spent several minutes blocking them and explaining the gag, played the title theme on a ghetto blaster and started shooting. An hour later we wrapped, stashed the lights, packed up the camera and that was that.
Once home, the dance sequences were captured into a MacG4 using the Pinnacle CineWaveHD system and the next week was spent building the sequences in Adobe AfterEffects5.0. At one point the post production crew stopped by to check on the progress. "Like any film guy getting into HD, I had certain qualitative budgetary issues that need to be resolved" says the show's co-producer Charley Cabrera, "having worked with Scott on other HD projects, I knew that he'd make it all work, but the look and dynamics of this piece are even better than we expected."
Since the sequence was shot entirely on HD, it made good sense to print to camera stock to pick up the cinematic nuance that HD laser printed to intermediate film stock is usually missing. We printed to Kodak 5245 (@ ASA 50) using the new Celco HD/Extreme film printer at the Burbank based Digital Image. The piece was screened a few days later and the director, producer and everybody loved it.
( QuickTime of the spot can be viewed at http://www.pixelmonger.com/screeningroom.html )
"I was initially hesitant to invest such a large block of the production in HiDefinition" says the film's post production supervisor Josh Levine "... but the quality speaks for itself. It cut in seamlessly and there's a lot to be said for a cinematic format that moves through post so effortlessly."
PRINTING BACK TO FILM
Donaldson continues, "Yes, I know that there are quite a few digital filters out there that do a very nice job of emulating the various signatures of film but they are all degratory. In many cases they are quite appropriate for broadcast applications but when it comes to cinematic film projection, there's nothing like adding the look of film by using real film". To quote my good friend Sean once again, "When you see HD on HD it looks like HD because it is HD. When you see HD on Film it looks like Film because it is Film."
While laser recorders are incapable of printing HD dependably to a camera stock, the Celco/HD line of film recorders do an exceptional job of breathing a film like nuance into the binary image structure of HD. With and ever expanding choice of emulsions for use by digital filmmakers, Kodak 5245 camera negative for HD acquired content and K5244 intermediary stock for HD that was originated on film seem to be the main contenders.
"When making the decision of which type of film stock to print to there are of course trade-offs," comments Bill Fightner, of Hollywood-based EFilm. "Both camera stock and intermediate stock have the potential to make your HD look stunningly cinematic. While printing HD to a camera stock guarantees you the addition of grain and the cinematic nuance of commonly used film types, the intermediate stocks from both Kodak and Fuji offer a slightly wider range of colors. In some instances, the colors in your HD data stream might not even be available in a camera stock."
We've been printing video to film since the late Eighties when, with the help of up-conversion algorithms developed by Digital Domain co-founder Price Pethel, we created and printed 65 effects for Roger Corman's unreleased epic THE FANTASTIC FOUR on an ancient Solitare. Whether dealing with ITU-601 or HD, it took as much craft back then as it does today to wrangle a film-like look out of video.
With proper care, HD becomes a powerful imaging medium that extends the range of expression possible with film. It isn't an 'either/or' situation. As always, the choice of recording environments depends on the needs of the project and understanding the capabilities and limitations of how film and HD work together.
The hybrid use of HD and film is essential for filmmakers in cinema's second century.
One of the projects that we used more than one flavor of HD on was Director Irving Schwartz's latest film LArceny where all of the principal photography was again, shot in 35mm. There were a number of rather long visual-effects sequences that needed to be created and since the file size of the digitized sequences exceed the capacity of Spirit's disk recorder, we captured the HD data streams to Panasonic D5 tape in Segmented Frame (SF). 
For Faye Dunaway's directorial debut, THE YELLOW BIRD (see DigitalCinema 2/01), we shot the entire movie using the "Panavised" (as in Panavision) Sony F900 HDCAM. Although the movie wasn't a particularly effects heavy project, Dunaway wanted to shoot on HD because as she says, "It's exciting and fresh, and I wanted to explore this new world of digital production." 
As mentioned earlier, LArceny director Irving Schwartz had became comfortable with the concept of mixing film and HD. As his movie began nearing the final stages of post production it became obvious to him that the opening title sequence just didn't measure up to the uniqueness of his story.
After all the work is done comes the last big hit to your shrinking production budget. David Donaldson is the is the guy that keeps Digital Image's tape-to-film division humming. His Yoda-like wisdom has saved more that a few of us HD Rambos from disaster. "As a basic rule of thumb, you should print anything that was originally acquired on 35mm to a tight intermediate stock so as not to pick up any extra grain and film character artifacts. Digitally acquired footage on the other hand will generally still look like really good video even after printing unless you record it to camera stock". 
