In the past 60 years, outdoor exposure with concentrated solar radiation has become an important test method in accelerated weathering. [1] This is reflected in established international standards and test methods (see e.g. ISO 877-3 [2], ASTM G90 [3], or SAE J1961 [4]). The use of natural solar radiation often results in degradation processes that are very similar to those of static outdoor exposure. Traditional solar concentrators mostly use ten flat mirrors in Fresnel arrangement, which track the sun in order to concentrate the natural solar radiation on the test area ("EMMA", "equatorial mount ...