Thanks. ok. Depth of Field Calculating Ring. I can't find any information on how to use it. I understand depth of field but can't make any sense of it. Mabe I should take a deep breath.
The blue ring has distance marked on it. The distance you're focused at is on the side of the camera. Use the focused distance and the distance mark on the blue ring to the aperture scale on lens to see the depth of focus/field. Hope this is clear enough.....