Marking OK: Displayed when the prism value measured at the current measuring position falls below a predetermined threshold value. In 5P
mode this threshold value is 0.03 , in 10P mode 0.06 (see description of Prism mode parameter, page 35) The measuring position then lies with a sufficient degree of accuracy above the optical center of the lens. In this position, the optic center and the direction of the cylinder axis direction can be marked using the marking lever once the angle has been set (see section Marking the focus and cylinder axis, page 57).