nedsram wrote:
I now understand that this is probably because the camera has run out of film - in this case I am informed that the camera reduces the threshold.
Not automatically, but if 'they' replace the camera etc. with a dummy flash unit then they may well set it to a lower activation speed. Also the dummy unit may not be as accurate.
If you look closely at the camera hole (top left) you should be able to tell if there is a camera in there or not. If there isn't one and it's flashing then it has to be a dummy unit.