The three-dimensional surface geometry of the cutting front during laser cutting and of the capillary during laser beam welding were determined from their local emission of thermal radiation. For this the emitted radiation was measured at different polarizations. The analysis of these measurements by means of Fresnel’s equations provides the local orientation angle of the surface element, which emitted the thermal radiation. By imaging the processing zone on a camera chip, the local emission angle of the observed surface is obtained for each pixel. The application of a highspeed camera allows for measurement rates above 70kHz with a spatial resolution of 30µm/pixel.  This enables to capture the dynamic response of the cutting front in case of spatial beam oscillation at 600 Hz. Investigation of electron beam welding processes showed high dynamic changes of the capillary geometry in case of spatial beam oscillation with up to 10 kHz. Latest laser sources provide coherent beam combining of 32 fiber laser. This technology allows for the creation of almost arbitrary beam shapes and to change them in the range up to 10MHz. In the talk we will present an analysis of the dynamic response of the capillary geometry on dynamic beam shaping at such high frequencies.