Elongated lighting system comprises an elongated light pipe having first and second ends, with light supplied to those ends by at least one light source, via first and second light couplers that condition light to increase reflections within the light pipe. Light-extraction structure on the light pipe extracts light from the side of the pipe. An indentation in the light pipe has a depth and has surfaces oriented with respect to the pipe so as (1) to redirect light from the first light source that reaches the indentation after passing once through a plane adjacent the indentation, back through the plane and towards the first end; and (2) to sufficiently increase the average angular distribution of light reflected from the indentation and passing back through the plane as would cause at least 50 percent more reflections of the foregoing light within the pipe in the absence of the light-extraction structure.