Inside the R-D 1 rangefinder < Previous | Back to index | Next>

These screws adjust the position of the moving rangefinder image by shifting the swinging lens's frame. The leftmost screw moves the swinging lens to and fro (up and down in the picture) to focus the moving image for a clear view. The center screw moves the swinging lens left or right to line up the rangefinder image at infinity. If you look carefully, you can see that these two screws are eccentrics: Their shafts are off-center and ride in slots. This means that if you turn one of these screws through one full turn, the swinging lens frame will move as far as it can go in one direction, then reverse itself and move back the other way. Why this is important: You can't count on, say, a clockwise turn ALWAYS moving the RF image in the same direction - once the eccentric reaches its limit, it will reverse direction. The large gray vertical adjustment screw at right works differently and is shown more clearly in the next picture.