The 4nm filters are equally suitable for use with a dedicated CMOS astro camera or with modern DSLR and system cameras.

The 4nm Narrowband-Emissionline filters suppress stars even more than the 6nm filters. Compared to the 12nm filters, the number of stars is only about one third. Even extremely bright stars are captured very discreetly. If you regularly use the "Remove Stars" function during image processing, the 4nm filters are the best choice for you!

The 4nm filters are available in threaded cells or with a protective ring.

Astronomik MFR and MaxFR coating

The MFR coating ensures that Astronomik Narrowband-Emissionline filters can be used with almost all instruments. This means you don’t have to buy different filters for different focal ratios, as it is the case with most competitors. Unlike filters from other manufacturers, which often require special “high-speed” versions, Astronomik’s MFR filters keep their transmission properties with both fast and slow optics.

For extremely fast optical systems such as the Celestron RASA and Takahashi Epsilon Astrographs, Astronomik currently develops the MaxFR coating for 4nm filters.

Both the Astronomik MFR and MaxFR coatings offer needle-sharp stars, extremely high contrast, minimized stray light, no halos and the best possible blocking across the entire spectral range from UV to IR.