One of the underwing tanks could be the modified version used to carry photoflash for night time operations. Not sure how widespread that was, but you can see it on this pic of XV406 (which was the Recce trials aircraft, so carries the pod and modified tank in spite of being with 111 at the time)
From what I saw of night recce film coming out of the processing machines, the electronic flash effectiveness was pretty marginal. Special high speed film (N7H) was used but we were always tweaking the machine speed/temperature settings trying to coax an image out of it. Worked alright when there was snow on the ground though! IRLS & SLAR was OK of course. I always wondered how the crews would feel about flying over enemy-held territory with great flashes coming off the aircraft. I seem to recall a II(AC) Sqn aircraft pausing outside our HAS for the film to be unloaded after a low-level night recce sortie. The navigator unexpectedly climbed out, threw his bone-dome onto the floor and swore never to do it again.
