The Vinten viewfinder system is a fascinating mix of old and new. It makes use of 2 prisms, one at the movement and one in the door. The prism in the door rotates in and out of the viewfinding position to send the light bundle to the eyepiece. There is a relay optic between the prism and the eyepiece that moves toward or away from the prism in order to show a magnified or regular view of the ground glass. There is a secondary position for the prism, but I have not figured out its purpose yet. The prism can also send images from the eyepiece through an opening in the door. Most of the components inside the viewfinding system were either frozen in petrified grease, or jammed in place by rotting black flocked paper. To repair this, the entire assembly was removed from the camera door, completely disassembled, and cleaned. The first thing repaired was the eyepiece light trap that was locked in the open position. The black flocked paper was scraped out and the remnants used to create a pattern for a new black flocked part. All of the optics were cleaned, the mechanical components cleaned and lubricated, and the door reassembled.
