2(AC) Sqn F4s also used the electronic photoflash pods, although they were generally almost useless for producing usable imagery. They had been designed and then rejected by the US - and then bought cheap by the RAF, whilst the USAF continued with photoflash cartridges. Main disadvantages were that the light output of the electronic flash was small, so ac had to fly very low to allow the light to reach the ground - not popular at night. Repetitive light flashes also tended to give AAA a good pointer towards a good target. Photoflash cartridges went off behind the image-taking ac, from a reasonable height, and thus also gave nice clear images with shadows to help analysis - Electronic flash was directly above the point where the camera was synched to open shutter so image was flat, grainy and shadow-free where you wanted to look. Luckily, we had the AAS-18 IRLS in the recce pod, which was superbly tweaked to make up for the deficiencies of the flash. 2 Sqn won Royal Flush Day/Night recce competition at Florennes in 73 (or 74) against USAF F4s who had the photoflash, mainly because of the performance of the IRLS. Both teams were obliged to produce annotated target imagery from the optical flash cameras, although ours depended almost entirely on using the IRLS as the prime.