The reticule in the scope was placed on a point of reference, for instance a church tower. On the map the angle as seen from the observers position was measured. For instance 1.250 mills. The main scale on the aiming circle was, during installation, set to 1.250 holding the church in the middle of the reticule. Aiming circles made it possible to measure the angle very precise.

This is the Messkreis for the Pz.B.F series.

  • 1. main scale showing the angle in thousands (Strich), 360 degrees is 6.400 Strich
  • 2. indicator representing the center of the reticule
  • 3. knob for fine tuning
  • 4. unlock mechanisme for a quick turn of the periscope
  • 5. indicator scale for fine tuning, acuracy 1 Strich

The same principal was applied on a smaller version, for instance for the SR-4.

Or even one step smaller, used for binoculars and “rabbit ears”. (Ebay)