Usually, this is a scarcely noticed and immediately forgotten seagull or rook, flying across the field of view. This can be frozen by the camera, with a wing upraised. If this looks like a head and neck then the photo enters the evidence. If it looks like a seagull, then it doesn’t. Boats tend not to be remembered either. Foreign bodies within the camera can also cause marks  on the film.

Speck on the film :
Courtesy: Brenda Meek

© A and M SHINE