Back Button


Berger fine adjustment

Fine focus is via the Berger side-fine-adjustment. The left fine focusing knob is graduated as the plate states, in 0.002 mm increments. Because of space limited on the plate by its retaining screw, the letters mm are on top of each other rather than next to each other as normally would be the case. The exact signature on the fine focus plate is: '1interv.' 0.002mm' (but the m's are on top of each other). The adjustment acts via an endless screw that acts on a gear which turns the vertical screw which raises or lowers the tube. The screw also acts, at the same time, on a gear that rides on another screw. As the gear rises or falls it reaches the inside edge of the housing above or below, which limits its travel, and therfore prevents the fine focus from going to the point of disengaging the focusing screw completely. Zeiss Berger Fine Focus control