The invention relates to an imaging optical inspection setup for inspecting a sample (5). Said inspection setup comprises a source of light (3) illuminating a specified portion of the sample surface by non-collimated light (4) in a plane of illumination, at least one pinhole (7) arranged in a path of reflected light (4′) reflected from said portion and/or in a path of transmitted light (4″) travelling through the entire thickness of the sample (5) in said sample portion, said pinhole (7) extending at least in the plane of illumination, and at least one screen and/or at least one position-sensitive detector system (8) arranged in the path of light (4′, 4″) passing through said pinhole (7) and adapted to intercept said light (4′, 4″), said detector system (8) being susceptible of sensing light intensity distribution along at least a line.