What specialized filters are required to bring out the fine detail of the Veil Nebula's filaments against the dark sky?

Hydrogen-Alpha (H-alpha) or doubly ionized oxygen ([O III])

Although the overall structure of the Veil Nebula can be discerned with standard astronomical equipment, revealing the delicate, thread-like filaments requires specialized narrowband filtering. These filters isolate specific wavelengths of light emitted by the energized gas, effectively blocking out the general background light pollution and the broad spectrum from surrounding nebulosity. The most crucial filters target emissions like the Hydrogen-Alpha line (often mapped to red/orange tones) and the emission line for doubly ionized oxygen ([O III]), which allows astrophotographers to capture the extreme contrast between the bright, defined knots and the vast, nearly transparent structures of the expanding shell.