I apologise for this grossly over enlarged image, but it was the only way to include an image of the Digerud Søndre light.  I think that the North and South lights at Digerud function as a range pair but I haven't been able to establish this with any certainty.  The relative height of the two towers, however, would strongly suggest that this is the case.  The Søndre light is the shorter tower in the centre of shot.  The construction vessel is also visible in this shot just to the left of the light.  And in the bottom right corner is the very tip of the Askholmene light (but even I haven't got the brass neck to add that to my list of sightings!).