Narrowband filters are a fantastic astrophotography tool when it comes to imaging during times of high light pollution. When all three filters, the H-alpha, SII, OIII filters, are used in unison, it is perfect for tricolor CCD astrophotography!
While narrowband filters do not eliminate the effects of light pollution, they do enhance the contrast between celestial objects and the night sky. It provides this contrast by reducing the transmission of certain wavelengths of light. These wavelengths come from artificial light, mercury vapor, and both high and low-pressure sodium vapor lights, and natural light, such as skyglow caused by neutral oxygen emission in the atmosphere. Additionally, each filter is fine-optically polished to ensure an accurate 1/4 wavefront.