With a lot of my scenic work where I need exact points -- near and far -- in focus, I determine the distance for each point with a tiny, inexpensive rangefinder. I then look up the f-stop AND the "center" distance I will need to achieve that using the DOFMaster for the lens I'm using. I then use my rangefinder again to select an easy-to-see point in the scene at that "center" distance -- and focus on it on the ground glass -- and stop down accordingly. Piece of cake, but becomes less and less useful the closer and closer you get -- i.e. close-up & macro work. My DOFMaster dials are made for normal distances, but, since you design them yourself, you could set them up for close-up use.