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Hurray for Dollywood

When the folks at Dollywood, the theme park of singer Dolly Parton, got the idea to convert a 100-seat theater from 70mm film to digital?and add 3D to boot?it seemed fairly logical. Such outsized ambition isn't surprising when it's associated with a star known for dreaming big.

Hurray for Dollywood

When the folks at Dollywood, the theme park of singer Dolly Parton, got the idea to convert a 100-seat theater from 70mm film to digital?and add 3D to boot?it seemed fairly logical. Such outsized ambition isn’t surprising when it’s associated with a star known for dreaming big.

CHALLENGE: Convert 70mm film to 3D digital projection and make it all run in sync with an existing array of hydraulic, full-motion seats and special effects. By all accounts, the million-dollar renovation couldn’t have succeeded without installer Julian Angus, president of InoTech in Sarasota, Fla. “The challenge here was to write the software to be able to control the entire system,” he says, downplaying the myriad calculations and integrations needed to make the components work together.The theater has 25 pods that move independently. Inotech’s proprietary software, which Angus wrote himself in the C++ programming language, runs them from a new, high-end PC from Chassis Plans (formerly Industrial Computer Source), which mostly sells systems for factory automation. Angus also wrote a real-time operating system in C++ and closer-to-the-metal assembly language to give the software the agility to control a vast array of servomechanisms through solid-state, fiber-optic input/output relays from Opto 22. The computer also controls the exterior videos along with the lighting and automatic doors.In establishing its requirements for the project, Dollywood set a high bar for film reflectivity, image quality, and size that Angus, through extensive research and careful calculation and design, was able to reach. “It’s getting harder and harder to tell the difference between film and digital projection,” Teske says, “[but] when you’re talking about brilliance and sharpness, film is still the standard to beat.”

Two stacked Digital Projection Lightning 45HD-3D projectors shoot separate left-eye and right-eye images through polarizers to create the 3D effect.

Credit: Julian Angus

SOLUTION: Calibrate two 3-chip DLP projectors to throw separate images from a content server, blended through proprietary hardware. Then, choreograph lights, seats, and special effects from an industrial-strength PC.

When the folks at Dollywood, the theme park of singer Dolly Parton, got the idea to convert a 100-seat theater from 70mm film to digital–and add 3D to boot–it seemed fairly logical. Such outsized ambition isn’t surprising when it’s associated with a star known for dreaming big.

But Dollywood is also rooted in business reality, and they don’t throw out the baby with the bath water. Any new technology would have to work with the theater’s existing, complex motion-seating and special effects system, a unique challenge for any AV integrator.

Not to spoil the Dollywood ending, but the challenge was met and over the holidays last year. Dollywood patrons stood in long lines to enjoy an ultra-realistic experience: a 4D, 12-minute abridged presentation of the Tom Hanks animated film, “The Polar Express.”

The public, of course, had no idea what went into the new Dollywood Imagination Cinema Theater.

From Consultant to Integrator

Credit: Julian Angus

In early 2008, Dollywood officials brought in Angus as a consultant to prepare specifications and send out a bid. After Angus made a couple trips to the 140-acre park in Pigeon Forge, Tenn., 35 miles southeast of Knoxville, Dollywood decided to hire him for the whole project and to scrap the bidding process. It didn’t hurt that Angus had a reputation as an expert on motion seating. Seven years earlier, while working for SimEx-Iwerks, where he was vice president of engineering, he had designed the hydraulic and electronic control systems and the sophisticated servomechanisms for the theater’s seating.

Tacked and Loaded: Tweaking Projectors For 3D

Besides enabling the move from film to digital, Dollywood’s two new Digital Projection Lighting 45HD-3D projectors are the centerpieces of the 3D experience. Installer Julian Angus says it would have been extremely difficult to do it in 70mm film because the reels on the two projectors could get out of sync, requiring physically removing frames from one strand to keep it running in lockstep with the other.

3D involves projecting two overlaid images that are, in essence, separated horizontally and vertically by two polarized-glass filters. “The images are drawn from two different angles, and that would represent the distance between your eyes,” says Dollywood’s Mike Teske. “The glasses you wear have one vertical and one horizontal, so there’s a left and a right eye.” He likens the polarizing effect to two window shades–one horizontal, one vertical–hanging in front of each other. “The right eye only sees the right-eye image, and the left eye only sees the left-eye image–unless you tilt your head.”

According to Steven Fackenthall, Digital Projection’s application support engineer on the project, Angus brought with him devices that generate the two images and feed them into the QuVIS Cinema Player. (Angus regards them as proprietary and is reluctant to reveal details.) The hard drive on the QuVIS makes synchronization easier by storing the right and left images and playing each at the right speed, say, 30 frames per second, according to Angus.

With image alignment so critical, the task of stacking and calibrating the two 249-pound projectors was given extra care. “We spent quite a lot of time on that,” Fackenthall says, including using a Sencore OTC1000 Colorimeter to measure brightness and color. “You have to match the light output of the projectors,” he says.

“When putting in 3D, the light from the brighter one will dominate that eyeball.” The brain will tend to ignore the image from the dimmer projector and the 3D effect is diminished, he says. Digital Projection consultants taught Dollywood staff how to shutter one projector while testing the light from the other, something they will have to do each time they replace lamps.

Fackenthall says getting the projectors to do 3D is important to parks such as Dollywood, which would prefer to focus their resources on the display devices instead of outfitting every viewer for so-called “active” 3D with a bulky, expensive, virtual-reality style headset. “The polarization happens at the projector, and the customer can wear 45-cent glasses,” he says.

Angus determined quickly that not everything in the analog theater had to go. Kept in place were the theater’s high-powered audio system, amplifiers, and Road Hog show-control console. “The sound is magnificent–it’s wonderful,” says Angus. “It’s six-channel digital. You think you’re there.”

But clearly the projection technology had to change. The two new Digital Projection Lighting 45HD-3D projectors offered the output Angus wanted. “These guys are 30,000 lumens each,” he says. The 3-chip DLP units have a super-sharp 2,048×1,080 resolution and powerful Xenon lamps. “One of the problems up to just recently was that the digital projection technology, as good as it was, was not good enough to project large images,” Angus says. “The DLP technology was critical because that is what makes the large and high-intensity projection [possible].”

“It was a unique application,” recalls Steve Sherk, Digital Projection’s regional market development manager. “A 60-foot throw distance and 60-foot screen. We had to make sure that projector was going to have the appropriate lens.”

The custom, 1:1-ratio lenses had to be distortion-free. Normally, there is room to play with throw distance by repositioning projectors, but there was little flexibility here, and the screen size was set. Plus, the lenses were fixed, so zoom was not a solution.

Not surprisingly, Angus and Dollywood workers spent a lot of time getting the 64- by 34-foot curved screen right for 3D. “If you go too curved, you don’t get a very tight screen because it tries to be lazy going around the corners,” says Mike Teske, director of maintenance and construction, who oversees all construction projects at Dollywood. “You want a tight screen so it is a vertical plane for the light to bounce off of. If it’s got a bow in the middle, it’ll be out of focus at the bottom and the top.” Great effort was exerted to stretch the seamless fabric over the frame, a process Teske likens to rigging a sail. “There’s a cone of good viewing for 3D. We wanted to have as big a cone as possible, and that’s where that curved screen helps.”

Screen materials were also key. “We could not use the original matte-finish screen,” Angus says. “It has to be aluminized. Once you go to a screen that is highly reflective, you want the light to go on the audience, not the walls, and you want to make sure everyone sees the same brightness.” He chose a high-gain (2.0), custom-made screen from Hurley Screen.

A QuVIS Cinema Player with JPEG2000 compression brings the flexibility and control that come with any move from analog to digital. “You can access any portion of the film, every frame,” says Angus, who sometimes refers to the device as essentially a hard drive. No more struggling with film’s tedious rewinds and counters. “It’s a very, very advanced piece of equipment,” he says, lauding the QuVIS documentation, which aided in software integration. The $28,000 device also comes with digital watermarking and other security features for downloading movies over the Internet. (Angus’s admiration turned bittersweet when Topeka, Kan.-based QuVIS announced it was closing its doors in December, though the company president told a newspaper he was seeking financing.)

The theater received some physical changes, too, many overseen by a local architect. Two four-seat “pods” were moved up to make room for stationary seats, and the opening in the projector room was enlarged to accommodate the beams from the stacked projectors, its quartz glass carefully replaced to minimize heat distortion. The exterior was fitted with retro, 1930s Art Deco-style signs, a marquee, and backlit movie posters reminiscent of old Hollywood theaters. Teske says the goal was to make it look generic enough to accommodate frequently changing shows, including this year’s planned digital version of “Thunder Road,” a Robert Mitchum movie that was the theater’s signature film for its first five years.

Dollywood also spiffed up the outside waiting area with monitors that show a looping, 10-minute preview. Patrons then enter a pre-show area with video that gives further information about the show, including safety requirements and warnings about motion sickness.

Research in Motion

In the projection room racks, a booth monitor lets operators check the auditorium. RF e-stops (the vertical blue boxes) talk to panic buttons below.

Credit: Julian Angus

It’s not unlike industrial automation. Angus says the software must not only send commands to individual hydraulic cylinders in each pod and monitor their pressure, it must get feedback from seat belts. The reason: safety.

Equipment List

Below is a list of the various AV equipment used by InoTech for Dollywood’s Imagination Cinema Theater. Some systems were already in place and needed to be integrated with the new digital systems.

  • 360 Systems PP1000 (solid-state digital playback)
  • A.C. Sound 4-channel repeaters
  • Chassis Plans industrial computer
  • Crown CT-210 amplifiers
  • Digital Projection Lightning 45HD-3D projectors
  • Gefen HD-SDI to DVI PLUS scaler box
  • JBL 4675C and 8330 speakers, 4642-8 subwoofer
  • Magnavox 42-inch 1080p HDTV monitors (waiting area)
  • Marshall Electronics V-R72P-HDSDI rack-mounted monitor
  • MicroAudio 2.5 CO equalizers Opto 22 relays
  • QSC Audio EX1600 amplifiers
  • QuVIS Cinema Player Sencore OTC1000
  • Colorimeter Simex-Iwerks Motion Seating
  • Sony DVP-NS75H DVD player
  • Radio Design Labs STP-1 universal audio attenuator
  • Ultra*Stereo Labs CM-80 booth monitor
  • Yamaha MG12/4FX mixer

Source: Inotech, The Dollywood Co.

“If someone decides to unbuckle their seat belt, the system will stop automatically,” Angus says. The recent software upgrade provided a further benefit, says Teske, by allowing operators to resume a movie where it left off instead of having to start from the beginning and evacuate the entire building, which had been the case when a pod went into emergency shutdown.

“It’s very unique software because it controls the motion of the seats and all of what we call the 4D effects,” Angus says. 4D effects are the atmospherics that add realism to the 3D experience, things like fog, smoke, and wind–plus, in the case of “The Polar Express,” the smell of hot chocolate. The show employs no water, mist, or snow, except in the outside lineup area, despite the obvious connection to the movie. “It gets messy,” Angus explains.

Prior to all this, Angus had synchronized the motion seats and 4D effects with the movie. “As we ride the film and run it with a joystick, the computer remembers the motion, and we simply record and play back,” he says. “It’s what we call the ultimate adult video game. The joystick does the actual motion. It tells the seats whether to move up and down, roll, pitch, yaw.” The seats move in 6DOF (six degrees of freedom), and operators use terminology from the flight simulators used to train pilots: “heave” for up and down and “surge” for front to back, for example.

“As we run it, then we click where we want the water, or the smell, or the lights,” Angus says. The user presses a key to mark the frame where he wants the effect to begin, then decides how long it should last. Angus says a five-minute film can have 6,600 frames, “and each of those frames can be addressed with an effect.”

During this process, Dollywood staff gives Angus input on the kinds of motions its patrons would find enjoyable. The park conforms to amusement-ride standard F24 of ASTM International but goes beyond it better meet the demands of its customer base, Teske says.

Angus says there were no big challenges in designing and installing both the AV and hydraulic components of the theater. If anything, rewriting his original software to integrate the QuVIS hardware with the hydraulics was challenging, requiring additional techniques such as SMPTE timing codes.

A Sight for Watery Eyes

Stacking and calibrating the two 249-pound projectors required precision–and a Sencore Colorimeter to measure brightness and color.

Credit: Julian Angus

Indeed, planners were concerned that switching in the same year to digital and the slightly smaller screen needed for high-resolution aspect ratios might result in an obvious loss of quality or image size. “We had a 70mm aspect ratio and that’s huge for our building,” Teske says. But Angus was able to maximize image size and resolution while optimizing brightness and the light reflected back to the audience.

Teske’s crew has an easier time maintaining the new system, though the hydraulic seats still sprout the occasional minor leak of lubricant or need their electronics replaced. “From a maintenance standpoint, our effort expended to maintain the image on the screen is greatly reduced because it’s all electronic,” he says. The cost of replacing projector lamps is a concern, but has been avoided so far. “What you save in labor you’re going to spend in light bulbs,” he says, an amount that Sherk pegs at $6,700.

Teske is impressed with the wonderful reaction from customers. “The biggest problem we’ve had is there are more people that want to see the show than there is capacity for,” he says.

Angus, too, seems proud of the result, noting viewers seemed touched by the “The Polar Express 4D Experience” attraction. “There were a lot of watery eyes,” he says.

David Essex is a freelance technology writer based in Peterborough, N.H.

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