Calcium-K (Ca-K) Solar Telescopes and Modules
Not only in H-alpha, also in the wavelength of Calcium-K the sun will show you many interesting events. Because deeper layers of the solar surface are observed in the blue Calcium-K light than in the red H-alpha light, other details emerge in this Ca-K wavelength. But the Ca-K wavelength is at the edge of the visible light spectrum for human eyes. Observers in their younger years can often see numerous things, but with increasing age less and less can be seen in this wavelength. However, all details could be captured photographically. Therefore, the Ca-K telescopes and modules are optimized primarily for photography.