Synthetic images of inner WISPR-I and outer WISPR-O telescopes combined. The images were produced with the fully fledged 3D simulation set-up introduced in Sect. 3.2. A mean background was subtracted from each image using a sliding temporal window ranging ≈5 − 10 h (running difference method). The relative brightness difference to this mean background is colour plotted with a symmetrical logarithmic scale (with linear scale below a cut-off value of 10⁻²). As the simulation is ≈22 h long, only a short temporal window around perihelion could be treated in a self-consistent manner (dynamic mode). Outside this dynamic interval, images were then produced with either the first or last simulation snapshot (static mode). An animated version of this figure is available online.