The invention provides an apparatus for producing an image of a global surface of an ion source sample plate that is exterior to an ion source. In general terms, the apparatus contains a sample plate for an ion source, an imaging device (e.g., a CCD or CMOS camera) and an illumination device that is configured to produce a light beam that contacts the sample plate surface to define a grazing angle between the light beam and the sample plate surface. The apparatus may be present at a location that is remote to the ion source.