What is focal variation?

Focus Variation is an optical technique used for high-resolution three-dimensional surface measurements. Its main component is a precision optical system that includes various lens systems and can be equipped with different targets. It combines the small focal depth of the optical system with vertical scanning to provide terrain and color information from focal changes. In other words, it provides information on the shape and roughness of the surface at once, which makes it highly efficient.

Basically, Focus Variation is applicable to surfaces with a wide range of different optical reflection values. Due to its flexibility in using light, this optical technology can avoid typical limitations such as measuring surfaces with strongly varying reflection characteristics, even within the same field of view. Samples can range from shiny to diffuse reflection, from homogeneous materials to composite materials, and from smooth to rough surface characteristics. Focus Variation overcomes the limited measurement capability in reflectivity by combining illumination, controlling sensor parameters, and comprehensive polarization. Modulating lighting means that the intensity of light is not constant, but rather variable. The complex changes in intensity can be generated by a signal generator. By constantly changing the intensity, more information can be collected from the surface of the sample.