Re: WHOOOAAAAA YEAH
Yeah, that's right, now that you mention it... they did have the film cameras in the sealed boxes mounted at the bases and tops of the stages to shoot the staging. That Apollo 6 staging footage with the falling interstage catching fire from the S-II blast is something I can watch over and over. They had those cams mounted inside the stages, just behind the engine nozzles, but they didn't have any outboard back-facing cams that I know of.
Btw, in most documentaries, that shot of the S-IVB pulling away from the S-II is usually cut way early; in the documentary For All Mankind, they use much more of that shot, showing the view from the S-II as it starts tumbling and falling. The effective POV is of someone hanging on for dear life to the inside of the engine fairing; it's really crazy-looking.