Distance Dependent Lens Distortion Variation in 3D Measuring Systems Using Fringe Projection

Measuring systems using fringe projection provide the possibility of very accurate touchless measurements. For the measurement of small objects compact devices are possible. However, in the case of very close distances between the optical system and the measuring object there is a considerable influence of the measuring distance to the lens distortion. This will lead to considerable measuring errors if neglected. In typical cases of our measuring systems the amount of the distortion may change by a factor greater than two in the range of a distance difference of a few centimetres. Results of the distance dependence will be given for the lenses of two devices.