Description
The working range of triangulation-based measuring systems is often limited by the depth of feld of the applied optical system. Approaches such as increasing the depth of feld range by reducing the aperture are limited in their efectiveness by a lower light yield and thus require a longer exposure time. Focus adjustable optics enable the depth of feld to be modifed and thus efect the location and shape of the working range. However, the validity of the model-based camera calibration is limited to the corresponding focus setting, especially with optics that exhibit the efect of focus breathing, i. e. whose focal length change with the focus setting. This paper presents an approach to model the calibration parameters over the entire focus range of a lens using function ftting of the camera parameters and the infuence of diferent confgurations on this process is examined.
