The invention generally relates to a compact, inexpensive-to-manufacture,
device of few components for optically inspecting a surface and a method
for same employing the device. The section of the surface to be
investigated is illuminated by a semitransparent mirror and a field lens,
employing a telecentric beam path, and at least part of the light
reflected or scattered by the surface is imaged onto the entrance pupil
of the optics of an electronic camera by the field lens, via the
semitransparent mirror. All optical and electronic components, along with
a light- and dust-tight housing, are carried on a specially configured
mounting block such that they are self-aligning. The method for
inspecting a surface involves automatically recording a series of images
of the surface under various types of illumination situations. Those
images are assembled into an image of the entire section of the surface
to be investigated and analyzed using known image-processing methods.