Originally Posted by rgraphex
If not the ribbon most likely a bad curtain. I had a few of these in the past dried curtain may look ruffled. You should be able to change speeds after winding.
If the curtains are dry, it shows up usually in the middle since this is the main part of the curtain exposed to light.
Dry curtains are like fungus... Once it starts it spreads out..
When a curtain appears ruffled at the top or lower corner if indicates a shutter tape has either broken or has come unglued from the shutter spindle...