H-a 5nm (1)
OIII 5nm (1)
SII 5nm (1)
Astrodon 5 nm Narrowband Filters – H-α 5nm$380.00 – $1,250.00
H-α (hydrogen-alpha) at 656 nm (nanometers) is deep red in color and the most popular narrowband filter. Hydrogen is ubiquitous in the cosmos and is present in emission nebula (North American, Pelican), planetary nebula (Dumbbell, Ring), Wolf-Rayet objects (Crescent, Thor’s Helmet) and supernova remnants (Veil). Many imagers like to present just a black-and-white H-α image of an object. It is has a beauty all by itself, like an Ansel Adams photo. However, most imagers blend their H-a data into their red RGB data to enhance structural detail while maintaining a “natural” look. Therefore, the H-α filter should be your first narrowband addition to your LRGB filters. The basic imaging set of 5 filters becomes LRGBH-α.
Astrodon H-α filters have a center bandwidth of 656.3 nmAstrodon 5 nm Narrowband Filters – H-α 5nmDoug WilliamsMarch 5, 2018
Astrodon 5 nm Narrowband Filters – SII 5nm$380.00 – $1,250.00
If you want the look of Hubble Space Telescope (HST) images, such as the famous “Pillars of Creation” (the Eagle Nebula, Messier 16), then the next filter to consider adding to your collection after H-a and OIII is the SII (es-two) or sulfur filter. The SII filter, like H-a, is a deep red filter near 672 nm. H-a, OIII and SII filters provide that Hubble look for many emission nebula. Again, tri-color narrowband imaging with these three filters can be done with the moon up, so your equipment is not sitting dormant for several weeks.
Astrodon SII filters have a center bandwidth of 671.6nmAstrodon 5 nm Narrowband Filters – SII 5nmDoug WilliamsMarch 5, 2018
Astrodon 5 nm Narrowband Filters – OIII 5nm$380.00 – $1,250.00
Bring Out The Faint Structures In Nebulae
Astrodon Narrowband filters set a new bar of performance and durability for imaging and research. We offer 5 nm and ultra-narrow 3 nm bandwidths.
Astrodon OIII filters have a center bandwidth of 500.1 nm.Astrodon 5 nm Narrowband Filters – OIII 5nmDoug WilliamsMarch 5, 2018
5 nm Narrowband Filters – RedCon$380.00 – $1,024.00
This Red Continuum filter (645 nm, 5 nm FWHM) produces a star map without the H-a or SII emission in order to subtract stars from emission images. Astrodon NB filters are renowned for not producing halos around stars and not leaking NIR light.5 nm Narrowband Filters – RedConDoug WilliamsMarch 5, 2018