Nodal Slide Assembly, Standard Equipment

Consists of  the following  itemsa)  Nodal Upright:  Consists of  a combination of Single & double lens holder on a  mount rotating along  the vertical axis. The combination lens holders are adjustable in height, and the single & twin lens  holders can either be moved together by rack & pinion or relative to each other by   sliding. These motions can be read by individual pointers on a mm scale.