I’ve been photographing the Sun for more than two years now almost each and every day, in a bit of a hackish way: using all kinds of filters beyond the 540nm continuum – hydrogen alpha – near UV calcium triad. However, as I advanced, I discovered that this knowledge is simply not common in the community, and not just that, it’s also a bit hard to come by while googling around. Also, to better explain double stacking, off banding and similar stuff, articles like this one Altair Astro’s 3nm CaK Ultra filter: testing, comparison, review are maybe rare.

So I put together an interactive tool to play around with spectra, in a way amateur astronomers find it interesting. The Spectral Composer.