Synthetic Ca II H and Hε images and spectral profiles for Hε emission formed at low mass densities. Top two rows: synthesized Hε line core images from a cutout of the Bifrost simulation calculated in 1D (top row) and 3D (middle row). Contours mark column mass regions, same as in Fig. 6. Bottom row: Ca II H plus Hε spectral profiles from locations marked with red crosses in the Hε line core images.