原帖由： Dan ,
Curtains! Your shutter is in need of lubrication. What happens is the opening or closing curtain is not going across smoothly so the exposure is off on one side. Oftentimes you’ll here a screech as the bearing is dry. Here’s a vid that helps explain things [https://www.youtube.com/watch?v=PJ3WTW0DvOk|Film SLR Shutter slow motion].