I recently bought Bronica SQ set (including Zenzanon-S 80/2.8 , AE metering prism and 120 back). First roll revealed some problem - dark "stripes" along the edges of the frame. They can be seen on the exposed area of negative only, not in the spaces between. Since it was an expired film, it is possibly damage of the film itself. However, on the next film rolls, problem still exist, altough not so obvious. Here it is on the right side - looks like vignetting along the edge of the frame. Here it is less prominent, on the right side too. I thought it can be a light leak in the back, but light leaks usually appear like light stiripes, not darker ones, right?