Narrowband Filters

This H-alpha Filter is suitable for imaging of Hydrogen nebulas from observation sites with light pollution and from dark sites as well. The FWHM of 6nm is matched to give you optimal performance with CCD and CMOS sensors with a very low dark current!

The OIII-CCD Filter is suitable for imaging of OIII nebulas from observation sites with light pollution and from dark sites as well. The contrast between an object glowing at 501nm and the background is increased enormous!

This SII-CCD Filter is suitable for imaging of SII-regions from observation sites with light pollution and from dark sites as well. The contrast between an object glowing at 672nm and the background is increased massively!

The Antlia SHO 2.8nm Ultra series filters are made with quartz glass and undergo precisely controlled coating processes to ensure optimal performance.

The Antlia SHO 2.8nm Ultra series filters are made with quartz glass and undergo precisely controlled coating processes to ensure optimal performance.

The Antlia SHO 2.8nm Ultra series filters are made with quartz glass and undergo precisely controlled coating processes to ensure optimal performance.

The Antlia H-Alpha (Ha) 3.0nm filter is suitable for imaging H-Alpha emissions from nebulae, planetary nebulae and supernova remnants.
The 3.0nm bandwidth delivers a high transmission at a center wavelength of 656.3nm

Narrowband filter sets are used to create high contrast deep sky images of certain objects, mainly emission and diffuse nebulae (i.e. Veil Nebula, M42 Orion Nebula, North America Nebula, Horsehead Nebula) or planetary nebulae

H-alpha filters are essential for imaging nebulae and other objects which are rich in ionized hydrogen.

OIII 3nm Narrow Band filters isolate the doublet emission of doubly ionized Oxygen. After ionized hydrogen, this is the next most common emission when imaging nebulae.

SII filters isolate the emission from ionized Sulfur atoms, also common in nebulae. Emission is at two lines occurring as a doublet, at 671.6 and 673.1 nm.

The next filter to complement your LRGBH-a set is an oxygen filter. OIII (“ohthree”) emits light near 500 nm and is a blue-green- or teal-colored filter. Many of my images of planetary nebula and supernova remnants are taken only with H-a and OIII filters.

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.

This is a bit complicated. It is not well known that most H-a filters pass both H-a and NII. H-a emits at 656.3 nm and NII emits most strongly at 658.4 nm (and weakly at 653.8 nm). These are very close together spectrally.

The Antlia 2.5nm Ultra series is designed with a FWHM (full width half maximum) of 2.5nm +0.3/-0.1nm and a transmission efficiency >93-95% at the Central Wavelength.

The Antlia 2.5nm Ultra series is designed with a FWHM (full width half maximum) of 2.5nm +0.3/-0.1nm and a transmission efficiency >93-95% at the Central Wavelength.