Difference between Astronomik 12nm, 6nm and 4nm Filters
The choice between 12nm, 6nm and 4nm half-width depends on your imaging conditions and camera type. There is no universally ‘best’ option – each half-width serves a specific purpose.
The 6nm Astronomik narrow-band emission line filters are usually the best choice for astrophotography. They are ideal for imaging faint objects in star-rich regions of the Milky Way, as they typically halve the number of stars in the image compared to 12nm filters, thereby significantly simplifying image processing.
The 6nm narrow-band emission line filters are particularly the first choice if you are using a CMOS astro camera or a modern system camera with very low dark current, or if you are conducting observations from a location with heavy light pollution. Thanks to their excellent suppression of the sky background, you can use long exposure times. The 6nm filters ensure a dark background and excellent rendering of details in faint nebulae.
