The use of microscopic techniques for quality control and product development has been in practice for decades. When there were no digital cameras, the view through the microscope with the aid of an eyepiece micrometer was the way to obtain reliable measurement results – for example for the visual measurement of a particle.
The image documentation was complex because it was done on film in the darkroom. The result report was according to an inspection manual, signed and then carefully filed away to meet the prescribed retention periods. Under the keyword “a picture is worth a thousand words” is the image-based report of a microscopic examination, supplemented by measurement data, a common documentation medium for describing defects, quality documentation and laboratory data.