Abstract: The invention relates to a simple and economic optical system for mutually positioning SMD components having connecting leads and the corresponding pads on pad carrying members with the object of bringing the connecting leads and pads together in one plane through translation or rotation, of positioning them and fixing them. The optical system utilizes a beam splitter, so that it is possible to observe simultaneously with the human eye the spaces in front of and behind the beam splitter. For considerations of robustness the semi-transparent mirror used to this end is evaporated on a transparent substrate which has a finite thickness. A substrate having finite thickness leads to an apparent displacement of the space behind the substrate relative to the space in front of the substrate. The invention relates to the compensation of this displacement by the installation of a compensation plate having identical optical properties in the space over the semi-transparent mirror on the substrate.