feSpotLight filter

parameters:

x = X location for the light source in the coordinate system

y = Y location for the light source in the coordinate system
z = Z location for the light source in the coordinate system

pointsAtX =X location of the point at which the light source is pointing.
pointsAtY =Y location of the point at which the light source is pointing.
pointsAtZ =Z location of the point at which the light source is pointing.

specularExponent =Exponent value controlling the focus for the light source. ( 1 by default )
limitingConeAngle =A limiting cone which restricts the region where the light is projected. Angle in degrees.

Tool: you can modify all parameters and see picture lighted with feSpecularLightning