Probably this has been discussed before, but I can't find a thread about it. A number of silent films (notably CABINET OF DR. CALIGARI) and early talkies (specifically M) have in certain scenes (but oddly, not all) a thin, semi-translucent horizontal line near the top of the frame. The postion of this line changes and is often not visible at all. It is not entirely transparent, though - within the line there is a refraction of the picture image below it. I have never found a satisfactory explanation for this. Were earlier prints on film and video cropped at the top (as I don't ever remember seeing these lines before laser and DVD), or are these different prints/negatives? Cropping these lines out would eliminate important information such as faces, so I can't imagine these were intended. Were these lines an error at the time of filming, or were they the result of later duplication? Any experts out there? I still enjoy watching these films and the lines are not a deal-breaker for me, but they are a curio. Thanks for any info.