From what I gather, the aft belly light was just behind the bomb bay and the forward light was in the hole normally housing the bombing camera which took several pictures in the 30 seconds after the bombs had been released to show where they had hit and to verify the target attacked. On the dams raid, the camera was virtually useless. The forward light shone straight down and the rear one shone forwards(obviously) to converge in a figure of eight pattern when the aircraft was at sixty feet and they both pointed in front of the leading edge of the starboard wing. I hope this helps.