If you are using the range finder, focus with the Optar on a set object, lock the focus bed, switch to the Fujinon, If the focus is off loosen two stops, and move them forward, then move the front standard until in focus, Lock in position then move the focus stops back against the foot of the front standard.
You must not use the focus adjustment while doing this. Maybe with a fine black marker draw a line across the track rail and bed, ti show the correct alignment for that distance.
Ian