Athens 2004: What are Data Links?
Data links are a method of getting camera data to radio linked cameras. This data allows functions on the camera to be operated remotely, such as exposure and colour balance.
This is mainly done so that all cameras are matched, so when the director switches between shots there isn't a noticable change in the picture. Other information is also transmitted which allows colour bars to be selected remotely (which is often used to check the quality of the signal being recieved), and also for a mixer 'tally' signal to be sent. This signal is sent when the camera is selected on the vision mixer and allows the camera man to know that their picture is live.
This picture shows an overview of the equipment used on one of the boats used to cover the sailing at the Athens Olympics. We had a total of 3 boats with this set up, and 2 helicopters with a similar set up at the sailing. The equipment in yellow was provided by Aerial Camera Systems, who I was working for.
I was also there to provide data links to two other helicopters which covered events in the city, such as the opening and closing ceremonies and the two marathons. I also had a truck mounted camera which was the marathon lead vehicle (with officials and timekeepers aboard) which required data.