The HEIDENHAIN ERN series encoders are used to position lenses in many of those large, high quality television cameras used in professional sports. Sportvision, Inc., known for their virtual Yellow 1st and Ten™ Line seen when viewing NFL football, uses these encoders to ensure accurate implementation of that process–and more–within the cameras.
“HEIDENHAIN ERN series encoders position camera lenses in television cameras, helping operators include special virtual effects like the Yellow Line for football. (Courtesy of Sportvision)
We have enhanced probably 200 lenses throughout the country with these encoders,” explained Rand Pendleton, Senior Scientist and Advisor in Sportvision’s Mountain View, Calif., location. “Besides our Yellow Line for football, our camera modifications facilitate all kinds of virtual effects including adding a lead-off line or the K-zone™ pitch effect in baseball, a “Glowing Puck” for NHL or putting a pointer to a car in NASCAR.”
Pendleton estimates that each television camera modified by Sportvision contains a $50,000 – $100,000 glass lens, and that their alterations allow the operator to do effects at every video frame, where they know the state of the lens, and basically where the camera is, where it is pointed, and what the field-of-view is. “From there, we can do our magic, from going from 2D to 3D or back.”
He explains that the modifications with the encoders came at the same time of HD technology and the necessity to be more precise. The key parameter of the lens is the accuracy of the field-of-view “which is why we mount the HEIDENHAIN encoders on an internal shaft in the lens that is mechanically adjusting the telescoping lens element inside the larger lens body.
High definition technology in the high end cameras requires lens to deliver an accurate field-of-view. Encoders help mechanically adjust the telescoping lens element inside the larger lens body.
“If it is an HD lens, it will have this encoder in it,” said Pendleton, “and one that is performing well since, once it’s in, we don’t even have to think about it. Then as part of every pre-game process, each lens is calibrated to go from encoder count to actual angular field of view, and thus the magic begins.”
Filed Under: Factory automation, Encoders • optical, Motion control • motor controls, Vision • machine vision • cameras + lenses • frame grabbers • optical filters