Coordinate measuring device for probing a workpiece, the probe head for a coordinate measuring machine and method for operating a coordinate measuring machine

A probehead (9) for a co-ordinate measuring device is disclosed, comprising: a probehead chassis (29), fixable to the co-ordinate measuring device, a feeler holder (39), fixed to the probehead chassis (29) and which may be brought out from a rest position, to which a feeler (47), for probing a workpiece (17), may be attached, a displacement measuring system (55, 57) for determining a displacement of the feeler holder (39) relative to the probehead chassis (29) and a tracking lens (61) for tracking a tip (49) of the feeler (47). The probehead (1) is characterised in that at least one of the components, feeler holder (39) and probehead chassis (29), comprises a transverse support (39), running transverse to the direction of extent of the feeler, which is a least partly transparent and arranged in the beam path (69) of the tracking lens (61).