what are the lights on the curling stone
Curling A handle is attached by a bolt running vertically through a hole in the centre of the stone. The handle allows the stone to be gripped and rotated upon release; on properly prepared ice the rotation will bend (curl) the path of the stone in the direction in which the front edge of the stone is turning, especially as the stone slows. Handles are coloured to identify each team, two popular colours in major tournaments being red and yellow. In competition, an electronic handle known as the eye on the hog may be fitted to detect hog line violations. This electronically detects whether the thrower's hand is in contact with the handle as it passes the hog line and indicates a violation by lights at the base of the handle. The eye on the hog eliminates human error and the need for hog line officials. It is mandatory in high-level national and international competition, but its cost, around US$650 each, currently puts it beyond the reach of most club curling.
Three-point lighting The key light, as the name suggests, shines directly upon the subject and serves as its principal illuminator; more than anything else, the strength, color and angle of the key determines the shot's overall lighting design.