With the Light > Lights Placement sub-palette you can adjust the light position. The controls do not affect the position of a Sun type light.
The Local Light Position Selector, active only for point, spot or glow lights, can be used to pick the light’s position on the canvas. Click on this button, and drag to the canvas to pick the position at that point. The X, Y and Z Position sliders will update automatically.
X Pos, YPos and ZPos
The Light Position sliders determine this light’s horizontal distance from the center of the canvas. These are set automatically when the ‘P’ picker (above) is used. To calculate the light’s coordinates, multiply these slider values by the average of the document’s height and width, then add the coordinates of the document’s center. These sliders are disabled when this light’s type is a Sun light.
The Light Radius slider determines the falloff radius for point lights, the focal radius for spot lights, and the glow radius for glow lights. To convert the value of this slider to pixols, multiply it by the average of the document’s height and width.