Shutter Curtain Problems in the Screw-Mount Cameras
First photo shows results from pin-hole light leaks in curtain(s) due to dried out rubberized side of curtain. Shutter curtain(s) needs replacing. Completely different problem- 2nd photo shows dark streaks throughout image due to the rubber from the curtain squeezing through the threads of the cloth curtain material. Following photos magnify the curtain. This only shows up on photos shot at high speeds since the opening slit between both curtains is so thin that even the slightly protruding rubber "bumps" will cause dark lines to appear in photo. Moving the arrow over the curtain photos magnify them. Replacing the curtain or curtains is best. This problem with the leading edge of the shutter curtain is not a problem with the Leica M camera curtains since they have metal leads.