The ZWO H-Alpha filter has a bandpass of 7nm centred at the 656nm wavelength, with light transmission close to 90%. This filter is a great choice for narrowband H-alpha astrophotography, delivering high-contrast imaging and revealing rich details of the nebulae even in areas with strong light pollution.

This filter can reduce the transmission of certain wavelengths of light, specifically those produced by artificial light including mercury vapor, and both high and low pressure sodium vapor lights and the unwanted natural light caused by neutral oxygen emission in our atmosphere (i.e. skyglow).

Technical Parameters:

Technical Data

• FWHM：7±0.5nm
• Fine-optically polished to ensure accurate 1/4 wavefront  over the both surfaces
• About 90% transmission at H-alpha line 656nm (H-Alpha filter )
• Infrared wavelength 700-1100nm cut-off
• <0.1% transmission of off-band, OD3 (Optical Density)