focus ring segment 40 reflecting surface 34 is formed by geometric curve 29 designated parabola c that is swept around axis x parabola c has a focus c 39 that is offset from axis x and therefore lies on focus ring 38 there are four focal rings 40 which correspond to the reflecting surface segments 36a 36d parabolas a and c have focus rings 38 in order to provide a focus that more closely corresponds with the phosphorous coated surfaces of tubes 30 this causes more of the light generated by the tubes to be properly reflected along the direction of axis a the four parabolas b which have focus rings 40 in order to provide foci that are even closer to conforming to the surfaces of tubes 30 as seen best in fig2 each reflecting surface segment 36a 36d in this first embodiment is proximate one of the tubes 30 the use of four reflecting surface segments 36a 36d is based upon a recognition that the light output from compact fluorescent lamp is not consistent radially around the lamp by reference to fig6 and 7 it is seen that as one travels from a 0 u00b0 position along the axis separating pairs of tubes 30 to an opposing position 180 u00b0 along said axis.