When you take pictures with this camera, you don't have to set distances, for the focus is fixed on this.
But if the subject you are taking is close to you, you have to turn the close-up knob to set the close-up lens (The left picture).
In addition to this, you can use the Y-1 filter to turn the filter knob when you take pictures with a B&W film.
You can use these filter only one at a time.