The Antlia EDGE H-alpha, OIII, SII Pro 4.5 nm Narrowband Filter Set is a premium solution for monochrome CMOS astro camera owners. This narrowband filter set, which is well-suited for use under light-polluted urban skies, features an extremely narrow 4.5 nm bandwidth that blocks other wavelengths.
The Antlia narrowband deep-sky filters offer exceptional contrast, allowing astrophotographers to achieve excellent results even under light-polluted urban skies or in the presence of moonlight. The Antlia EDGE H-alpha, OIII, SII 4.5 nm narrowband filter set guarantees over 90% transmission in the central 1 nm bands (OIII: 500.7 nm, H-alpha: 656.3 nm, SII: 671.6 nm), making it perfectly suitable for photographic use with very fast optics and telescopes. Even at an extreme f/3 focal ratio, there is only minimal transmission loss.
Compared to the Antlia 3 nm bandwidth version, shorter exposure times can be achieved, and the price is more favorable. In the OIII band, the 3 nm version provides greater contrast and its narrow bandwidth makes it more suitable for photography in areas with higher light pollution.
In summary, the advantages of the Antlia narrowband filters are as follows:
- High light transmission and minimal bandwidth serve to maximize contrast
- The steep transmission curve minimizes halos around bright stars
- Can be used in both light-polluted and dark locations
- Allows for longer exposure times even under strong moonlight
- Low transmission loss even when using telescopes and lenses with an f/3 focal ratio
- The matte black paint on the filter edges prevents internal reflections of stray light
- Excellent optical quality reduces the need for image post-processing
- The filter material is high-quality Schott glass
- They have at least lambda/4 or better surface accuracy, indicating a premium category
- The optical surfaces are treated with anti-reflective and scratch-resistant coatings by the manufacturer

