1. An optical apparatus for locating a plurality of placement positions on a carrier object, the optical apparatus comprising: an imaging device comprising a plurality of imaging sensors, each imaging sensor being operative to capture an image of a part of a selected row of placement positions on the carrier object, and the plurality of imaging sensors defining a combined field of view that includes an entirety of the selected row of placement positions; a positioning device coupled to the imaging device, the positioning device being configured and operative to position the imaging device in a direction perpendicular to the selected row of placement positions relative to successive rows of placement positions on the carrier object; and a processor connected to the imaging device and which is configured to receive the images captured by the plurality of imaging sensors for image processing in order to identify exact locations of the placement positions comprised in the selected row of placement positions.