Abstract: A lamp comprises: an elongate support, a plurality of light directing members, and a light generating unit. The light directing members are supported by the elongate support at respective different positions along the length of the elongate support. Each light directing member is rotatable at least partially around the elongate support to select a rotational position of the light directing member from a respective range of rotational positions of the light directing member; Each light directing member cooperates with the light generating unit so that at any rotational position within said respective range of rotational positions of the light directing member, the light directing member receives light from the light generating unit and directs the light away from the lamp in a direction dependent on the selected rotational position of the light directing member.

Abstract: A lamp comprises: an elongate support, a plurality of light directing members, and a light generating unit. The light directing members are supported by the elongate support at respective different positions along the length of the elongate support. Each light directing member is rotatable at least partially around the elongate support to select a rotational position of the light directing member from a respective range of rotational positions of the light directing member; Each light directing member cooperates with the light generating unit so that at any rotational position within said respective range of rotational positions of the light directing member, the light directing member receives light from the light generating unit and directs the light away from the lamp in a direction dependent on the selected rotational position of the light directing member.

Abstract: A method and apparatus for determining in a ball game (for example, tennis) the position, relative to a service reference lines (12), of the first contact of the ball (14) with the playing surface. In play, the ball passes through a collimated light beam to intercept light directed at a light sensing array, which comprises many closely spaced sensors (46) arranged in column and row formation. A signal storage means includes one storage device for each of the sensors, so that the position of the ball may be tracked in the storage means as it passes through the light beam. The said position is determined by tracking in the storage means the front of the ball (14F), and for each sensed position of the ball front determining the then height (H) of the top of the ball, at a position displaced rearwardly one half the ball diameter.

Abstract: A method of determining in a game of tennis the point of contact of a service ball relative to a service line by (a) monitoring a field of view along the service line and producing an electronic representation of an upper boundary of the ball as it passes through the field of view, (b) scanning the upper boundary of that representation progressively in the direction of the ball flight and determining at successive spaced positions along the path of the ball the angle of definition of the boundary, and (c) comparing successive values of that angle and noting the position of the ball at which that angle reduces relatively rapidly to a lower or even a negative value. A preferred method determines and compares successive horizontal components of successive sections of the boundary which have successive equal value vertical components.