H-Alpha 2" 12nm filter from Explore Scientific is specially designed for astrophotography, providing an effective solution for capturing emission nebulae under polluted skies. This filter blocks almost all artificial light, notably that from mercury and sodium vapor lamps, and only allows the emission line of red hydrogen to pass. This helps to reveal hidden details and capture nebulae that would otherwise be invisible. With a bandwidth of 12nm, this filter significantly enhances the contrast and sharpness of deep-sky objects, even in urban observing conditions. An essential accessory for astrophotographers looking to obtain outstanding images despite light pollution. Each filter comes with an individual test certificate guaranteeing its high quality.