Corkscrew Hill

A Themed Attraction Using High Definition 3D Imagery
Williamsburg, Virginia

In 2002, Busch Gardens in Williamsburg, Virginia, opened a show that broke new ground in High Definition 3D imagery with a system provided by Electrosonic. Never before had full motion video been presented at a resolution of 1900 x 1280 in 3D on a screen as big as 44 feet x 30 feet (13.4m x 9.1m).

Corkscrew Hill was the lead attraction in the Ireland Country at Busch Gardens. The show was written and directed by Jeff Kleiser and Diana Walczak. The projection and show control system was engineered by Electrosonic, and was based on High Definition Server technology.

The main show was presented as a stereoscopic (3D) image, using dual projection and polarized images (with glasses), and an audience ride on a huge 59-seat motion base with six degrees of freedom. The attraction was constructed in an existing building and this imposed some severe constraints. In order to fill the audience’s field of view, a screen 44 feet wide and 30 feet high was needed, and to fit in the building a projection distance of only 24 feet was available. In order to achieve sufficient image brightness and resolution it was necessary to use two projectors to cover the screen area (then doubled up for 3D). Each projector was mounted on its side to project a portrait format image 1024 pixels wide, 1280 high. The side by side images overlapped by a small amount to give a net displayed resolution of 1280 high x 1900 wide. Total light output from the projectors was 48,000 lumens!

Corkscrew Hill

In order to achieve subjectively even illumination from all seats, it was necessary to ensure that the projectors were sited as close together as possible. This arose from the use of the silver screen surface necessary to retain polarization, and resulted in the need for lenses that permitted a big image shift.

The show was run from four Electrosonic HD Video Servers running in frame sync. The servers included the facility to provide soft edge blending of images, and this was specially tuned to match the needs of the Corkscrew Hill attraction. The servers outputted serial digital, so Corkscrew Hill represented one of the first ever attractions to use an all-digital production/presentation chain. One server generated time code for the audio system which used a multi-track hard disc drive as source.

To provide sufficient throughput for busy days, the whole installation was duplicated. Each main show had its own pre-show, and prior to this there was a common pre-pre-show. All the pre-show installations were also 3D high definition presentations, but on comparatively small screens.

Electrosonic engineered the entire audio-video presentation system, working closely with Busch Gardens project director, Larry Giles, the show producers Kleiser-Walczak Productions, the ride manufacturers CAE USA Systems (formerly Reflectone) and other contractors.