Lady Harry thought they'd missed a trick by not having a collection afterwards at each cinema
Back in the early sixties the film was shown for a whole week at the Stockton Odeon. Leading Cadet Blacksheep was one of the ATC 1261 (Thornaby) Squadron cadets on duty with collection boxes. I saw the film 19 times and we collected a record sum for the local RAFA Branch.
Later, at RAF Northolt I was privileged to discuss the film with Joe Kmiecik who flew one of the Lancasters in the film. He said they flew the dams in daylight and the cameras were 'stopped down' so that the result looked like night time. At 150 feet they were also a lot higher than the actual 617 Sqn raiders. He said he had no idea how they did it in the dark at 60 feet.