When U.S. Sports Video engineers began investigating design criteria for endzone camera systems back in 1990 one of the first questions considered was the appropriate height for the endzone camera. A review of then current practices, including the use of existing structures, bucket trucks, scissors-jacks, and others, revealed that, not surprisingly, the parameter of concern was angle of view rather than camera height. Line coaches with endzone video capability had already been determining their viewing-angle preferences, but usually were simply using whatever was available. In order to provide adequate height angle, large, heavy elevation systems, like bucket trucks, which had to be stationed some distance from the endzone, had to be considerably higher than scissors-jack platforms that could be located within the field.

Obviously, placing the camera system just outside the endline provides for a geometry that results in the minimum camera height to achieve a given viewing angle. Using this as a starting point U.S. Sports Video's earliest endzone systems were then field tested to fine tune the combination of viewing angle, stability, and cost to achieve an optimum range of products.

The initial EagleCam unit was an Eagle system custom-built to provide up to a 40-foot camera elevation for the athletic department at Texas A&M. Shortly after that system was installed and in operation a SkyHawk model was provided to Mount Union College where Head Coach Larry Kehres rigorously evaluated it and helped set the viewing angle and other operational parameters.

At the same time our engineers and coaches were testing various Eagle and SkyHawk models at various locations in order to evaluate engineering parameters that concerned safety, stability and performance.

These real-world studies revealed the critical importance of having a stable structure able to resist being blown over in all too common wind gusts seen in outdoor facilities. From a practical point of view this dictates that systems should be no taller than required to provide a good viewing angle -- which means they should be as close to the endline as practical.

An unexpected advantage of shorter distances was discovered during a comparison between a SkyHawk and a vehicle-mounted scissors-jack at Oberlin College. The SkyHawk was located within about 10 feet of the endline while the scissors-jack platform was outside the field at the opposite end and at an elevation of about 45 feet -- which still gave it a somewhat lower viewing angle than that provided by the SkyHawk. During the game it began to snow. The view from the scissors-jack mounted camera was looking through about four times as many snowflakes -- which rendered the image almost useless. The video from the SkyHawk's position was only slightly degraded.

Also of concern is the vibration generated in the resulting video by lack of stiffness of the tower supporting the camera. Both the Eagle and SkyHawk systems are designed to provide optimum stability and stiffness consistent with safety, portability and cost. Stability of the Eagle is established by the large base formed by the trailer jack and outriggers. SkyHawk depends on its large 10-foot footprint and on an auxiliary weight to resist toppling for camera heights up to about 30 feet. Stiffness in both models is provided by the large diameter aircraft aluminum tubing and unique custom-built couplings used in their construction. An earlier manual model, (newly christened the Raven), has recently been upgraded for the lower budget programs, and achieves acceptable stability and stiffness at the cost of locating the system just behind or very close to the endline and with the requirement that the videographer be exposed to the weather.

John C. Fakan, Ph.D.
Senior Product Engineer
800-556-8778
www.ussportsvideo.com