From the Star Wars prequels to the Lord of the Rings trilogy, the fantasy films of the twenty-first century have increasingly relied on computer-generated imagery to keep pace with their makers’ imaginations. So perhaps it was only a matter of time before some filmmakers decided to eschew practical shooting altogether and build an entire cinematic world from virtual scratch. That’s exactly what director Kerry Conran and cinematographer Eric Adkins have done for Sky Captain and the World of Tomorrow, the first live-action feature film produced entirely from blue-screen composites and CG animation.

Conran’s idea of an adventure film combining live performances and animation was hatched more than a decade ago, when he and Adkins met as film students at the California Institute of the Arts. Hollywood beat them to the punch with the release of Who Framed Roger Rabbit, forcing Conran to table his initial concept. However, as personal computers birthed a new form of animation technique, Conran rediscovered his muse. Several years later, utilizing costumed actors composited via blue-screen into computer-animated backgrounds, he and Adkins finished a six-minute demo reel for a retro-flavored serial-style adventure that pitted an intrepid war pilot against a legion of giant robots stomping through New York City. Producer Jon Avnet saw the reel and was impressed enough to shepherd a feature version of Sky Captain and the World of Tomorrow into production.

After ten months of preproduction in a Van Nuys warehouse, principal photography commenced with three Sony HDW-F900/3 CineAlta cameras shooting on a trio of giant blue-screen stages at England’s Elstree Studios (the largest comprising over 16,000 square feet with 50-foot ceilings). ICG spoke with Eric Adkins over the phone about his pioneering project.

ICG: You have a background in special effects cinematography, from blending CGI in commercials and music videos to doing stop motion work in features (Mars Attacks) and television (The PJs). How did this prepare you for Sky Captain?

ADKINS: On The PJs, we had six directors, forty-seven 35mm Mitchell cameras and sixty miniature sets in a 50,000 square foot building. So it involved a lot of organizational skills—troubleshooting, scheduling and figuring out efficient ways of shooting things. But you tend to take on extra responsibilities because you don’t want your crew to be relighting the same stuff all the time. So The PJs was a great training project for this blue-screen work on Sky Captain. Producers can say, “Well, the blue screen has no sets; you can shoot anything you want.” But even though you don’t have the physical reference, you still have to present lighting continuities with an efficient shooting order. The producers would have loved to get through 47 shots a day; we were consistently getting around 37 per day, which is still a lot of shots. It’s very interesting when you can take something from another job that was so unusual, and bring it to this job, which is also unusual, and really make it work for you in ways that aren’t typical to your job title.

ICG: Ten months of preproduction is certainly atypical.

ADKINS: When you’re shooting entirely on blue-screen and there are no physical sets, the process of discovery is so intensive in the front end to meet the challenges of believability and tactile involvement. You have to visualize how the imaginary place would feel, as opposed to just look. I was employed for ten months ahead of time to figure out all these obstacles to help with the believability, to help with understanding each “location,” to give a feeling from one room to the other. It’s even more make-believe than normal filmmaking; you inherit nothing, you have to create absolutely everything.

The first thing I did was go out and do some Los Angeles-based reference shooting with a [Nikon D1-X digital] still camera, going on roofs, looking at old marquees—essentially location scouting. All of the background plates that were not archival photographs, matte paintings or CG animations, I shot with Darin Hollings, [Visual Effects Supervisor] with this digital camera and no crew. We brought help in for some places like Radio City Music Hall in New York, but that wasn’t a crew for lighting—it was more like, “Hey Moe, can you stand over there as a reference?”

Also, if we wanted higher resolution, all we had to do was take a grid of digital photographs that overlay each other and then stitch them together. Meaning I would take one shot with an ideal framing; then I would tilt up the camera like half the width of the viewfinder and take another picture, and then pan over half the width of the viewfinder and so on—essentially getting nine photographs to make a much bigger square. We couldn’t use too wide of a lens—if you went any wider than a 32mm, the distortion would make it hard to stitch them together naturally. But with this stitching, you’ve exponentially increased the resolution, so then you could actually create “moving” shots; pans and tilts and 2-D zooms on the background plates. We didn’t even have any motion background plates on this film.

ICG: What previsualization techniques did you use?

ADKINS: Well, originally we were planning a lot more 2D and 2-and-a-half-D shots, where we might have a still or archival photograph and layer it on top of a slight 3D model. We were also planning to shoot most of the story in a dry rehearsal on the Van Nuys stage, so we would have a sort of live animatic. But when Angelina Jolie was hired and the backgrounds changed to be seventy-five to eighty percent 3-D, Kerry decided he was going to previsualize absolutely everything. So we decided to do the animatic all digitally.

Steve Yamamoto, the animation supervisor, would go through all the shots inventing dimensional storyboards, asking my opinion and using me as a bouncing board before he took it to Kerry. If there were especially dynamic shots, he would bring them to my attention and say, ‘Do you like this better, or do you like this?’ It was kind of like working with a camera operator, where you’re using the talents of someone who understands the equipment really well, and you work with them as a tool.

At the same time, I would study those previsualizations like they were a set and anticipate how the actors might be blocked based on conversations with Kerry. Then from that, I could tell where windows or doors or practical lights might be in the set and add lighting input such as which direction I might key from. I used these keylight notes to help organize how we were going to shoot it.

It didn’t always work. For example, when we were doing tech rehearsals on a mock-up of Sky Captain’s cockpit, [the animatic] would have us sticking cameras in physically impossible places given which camera rig we needed to use, or given the fact that the lens is so many millimeters long. In that case we actually had to throw the previsualized CG shots of the cockpit away. So before we had to send the plane off in a storage bin to England, we got our stand-ins back in there and did shots in every conceivable direction, so that the editor could then cut them [into the animatic].

ICG: How did you translate these animatic camera angles into physical setups on the blue-screen stage?

ADKINS: On a normal film you’d have the art director’s floor plan, and you’d sketch in where all your cameras and lights are. What we could do on the computer is essentially ‘highjack’ all the virtual cameras from the shots in that animatic sequence, and import them into a top-view floor plan of the virtual “set.” Then we could see exactly what our camera placements were going to be, and I would sit down with our tracking people and have them separate the scene into “clumps” of forward and reverse angles. Once we had those clumps together and made sure that they all fit in the blue screen field, we would lock and rotate them all together in relative space so I could arrange them according to how it would be easiest to light. For example, if the key light was going to come from 3/4 back on the right side, I needed to position that “clump” where I would have access to enough space in the blue screen to light from that direction. But I wouldn’t want to be dragging lights out onto the blue screen for the reverse; what we would do then was just essentially rotate everything around on the virtual floor plan and shoot it the other way.

ICG: How did the blue-screen shooting affect your lens choice and camerawork?

ADKINS: We originally planned to use Zeiss’s new HD primes. But we discovered that the true nodal point of these primes was different somewhere out on each lens, and so with every physical lens change, we would have a different offset that we would have to calculate into the computer design as pre-visualised. To avoid confusion, we didn’t want to recalculate for a lens change on the stage floor. Since all line-ups for composite must be measured from the nodal point and not the focal plane, when measuring the cameras distance and height. So I said, “You know what? The [Fujinon 5-50mm T2.4] zoom lens isn’t the newest lens out there, but it seems to be very consistent nodally through out the range, and when you follow focus, it doesn’t breathe at all.” So we used those zooms for the whole show.

We were also discovering some very “anamorphic”-looking noise in the [camera’s] blue channel—if you were shooting film you would call it “grain”—which was stretched out and kind of had a halo to it. The blue channel is so noisy because it’s the last chip at the end of the prism and it’s working so much harder to sense the light through all those layers of glass. We set the camera’s gain control to -3Db—which is essentially making it work less hard to sense the light, the opposite of pushing a film stock—and all of a sudden the blue channel became normal looking. Which was great, but by doing that we lost another two-thirds of the light. So we found ourselves down to shooting at a 2.8. But some people shoot HD wide open anyway, to gain a little bit more of a 35mm look in terms of depth-of-field.

We never shot three cameras at the same time; the third camera was purely for pre-setting on another set to buy us time for relighting. We also knew we were going to do A-B type camera set ups, but there were times early on where we actually spent more time trying to make a setup work for both shots simultaneously than we would have if we just shot one after the other. So I had the idea to use that same amount of time to set up an A and B camera, but not always shoot an A and B camera. You could set up one camera that might actually be in the shot of the second camera, but because it was on a crane with a remote head, you could shoot that camera and then say, “OK, that’s done” and lift it out into the sky. Now you’re ready to shoot the next shot, which is already set up.

There was no motion control on this whole show. Instead we had this thing called a “camera orientation device” that Darin’s brother made for him in the welding shop. It looked like an antenna, and by mounting it on the camera, you could tell that it was tilting or panning so many degrees and how high it was off the ground. With a regular surveying laser pointer, they were able to ping every single spot on that targeting device, and we were able to track any moving shot on computer software back in post.

There was even one shot where we needed a very accurate matte, and we actually turned the HD camera sideways on the full-body shot of a guy standing there. You get all this extra edge detail that is much higher resolution than the vertical resolution. So you can actually use the horizontal resolution as the vertical in blue-screen, because there’s no up or down.

ICG: What other tools did you use to establish the look of the film?

ADKINS: I couldn’t soften the images traditionally, because it’s blue screen—you want them to be as crisp as possible. But I wanted a softer look on the faces; I didn’t want the sharp, harsh, highlight tones that a digital chip gives you. So I decided to shoot the whole film with a polarizing filter. When you’re side lighting and backlighting, it takes the harsh glare away, but doesn’t get rid of the source. It makes it more velvety, like some of these old silver nitrate prints from way back when. Of course, you also immediately lose almost two stops of light—on top of what you lose from shooting at -3Db—so you have to light things brighter. I tested it out to see if we had enough light, and it didn’t change anything technically that would have hurt pulling the keys.

ICG: How did your lighting differ from a traditionally shot film?

ADKINS: Some of the early press seemed to be saying, “You can practically light this all in the computer.” Well, I knew that wasn’t going to be the case and so did the director. At first it was thought maybe we could light flatter [than normal], but that was proven not to be true. We needed a much better, more realistic lighting solution because this was film noir: There’s a lot of back light and side light and silhouette. If you have someone walking in a scene, going in and out of light, it’s so difficult to recreate that realistically in a 2-D lighting session in the composite stage. If you put that task onto the compositor to recreate, it wouldn’t be afforded for the whole film.

At the same time, to get an ideal key, you want to light for your blue screen. You want it to be even and consistent, and therefore you base everything on that [exposure]. From the T-stop that you get, you’re only going to mess around with it plus or minus two thirds of a stop. And then if you can, turn the blue screen off so you can light the characters. That’s one of the best tips you can say to anyone lighting blue screen, because they can get so disoriented by it that they don’t even feel through the blue. Once you get it right, why don’t you turn it off? You already know your T-stop, so then just begin to light.

ICG: Did lighting for the blue screen pose any special challenges?

ADKINS: I knew that I wanted a larger radius base ramp, than most contractors like to build for reasons of amount of materials used.  But if the ramp is too tight light gets amplified, like in a cylinder, which gives a horizontal highlight, behind the actors’ legs, in your blue screen.

You also have to consider the fact that you’re also lighting the blue screen floor that they’re standing on. It’d be easy if everything was a medium shot and you had a blue screen that everyone was standing in front of on a platform. But you have to take into consideration that the actors are walking on the same blue floor that they have to be keyed on, and you want it to match the wall behind them.

However, you don’t want the movie to just be technically lit to be good for key. There are times when you do have to sacrifice a perfect key pull for drama’s sake. You learn to rank things in terms of importance. For example, in one scene the characters were supposed to be walking through a mineshaft. That was some of the ugliest blue-screen floor lighting you can think of, but everything from their knees up was in a nice blue field and everything down lower was essentially unlit anyway, so it was essentially a silhouette and they could pull a key off of that. You want it as clean as possible, but if the action was good, moving on is a good thing to do. That’s what’s good about having a director who knows what he’s doing in the digital composite world.

ICG: Can you describe your lighting for one scene in particular?

ADKINS: There’s a scene set in Sky Captain’s office where Jude Law and Gwyneth Paltrow meet for the first time. We actually shot it a whole half a week early; it was supposed to be a rehearsal, but everybody was just ready to do it. This was my only opportunity to test with the real actors, without the pressures of actually having to live with it in the movie; I was taking more chances with the dark, noir-y look. I wanted to be able to put Jude Law’s face in complete blackness with a slight edge around the back of his head leaning against the door frame.

We specifically designed this intimate scene to be some of the first shots because it was a close confined space. It was less about the walls; it was more about the desk and the doorway. It felt like theatre to the actors. For this tight room I had a 9-Light with 8x8 full grid diffusion boxed in so it didn’t spill on the bluescreen. What I wanted it to do was also light a large cabinet behind him, which was essentially a “wall” reference. Between the practical doorframe and the big cabinet, there was a gap where you saw into the bluescreen background behind. If I was on a real set or a location, I’d be forced to use an unnaturally high-angled light or put a light near his feet to illuminate the cabinet.

But this way, since there was no real wall there, I just had to angle the cabinet into that 9-Light coming through the space between it and the doorframe. It nicely rendered this really soft glow, and it was totally convincing that it was supposedly coming from that window in the office door. So I was able to use the fact that we were shooting on a blue screen to enhance the scene.