I first saw this video in 1981 when I was at Ft. Rucker, AL., going to Aviation Safety Officer's school. The instructor had it running on the screen on an endless loop tape as we entered the class, and asked us to identify what we were looking at.
It took us a while, because we were actually confused by the intermittent passing of the tail rotor.
I think the helicopter in the video is a Sikorsky S-58, (CH-34).
The video is narrated in German.
Here's the translation:
"The rotortips absorb the turbulence with their flexibility. This recording was made, during flight, by a camera mounted to the leading edge of the rotorblade. At every turn you can see the tailrotor. If the flexible rotorblades wouldn’t absorb the the forces, they would be transmitted to drive mechanism and fuselage and the vibration would destroy the helicopter."
After watching the contortions the rotor makes, I wasn't too sure I wanted to get back into a helicopter!
I found this link at http://www.rapp.org
There are more interesting aviation videos there, if you want to take a look!