ZWO 36mm SII Filter - 7nm
The SII Narrowband filter transmits only Sulfur-II wavelength light, which is found in most nebulae, star clusters, galaxies, and stars. This makes these filters ideal for complex false color imaging of such regions. SII filters such as this one are excellent for boosting contrast and are most definitely a must have for imaging in areas with high levels of light pollution. This particular SII filter has a bandwidth of 7nm.