ZWO SHO Narrowband Filter Set
The ZWO SHO Narrowband Filter Set contains one H-alpha, one OIII and one SII filter. Use it for tricolor CCD astrophotography. Available in 1.25″ & 2″ round mounted sizes as well as 31mm & 36mm round unmounted sizes.
The ZWO H-alpha 7nm Narrowband Filter has a bandpass of 7nm and passes light at 656nm wavelength, light transmission rate comes up to 90%. Best choice of narrowband H-alpha astrophotography filter for high-contrast imaging and revealing rich details of the nebula even in areas with strong light pollution, just prepare to experience the infinite fun with it!
The ZWO OIII 7nm Narrowband Filter is designed for nebula observation allowing the 7nm bandwidth of light centered on a wavelength of 500nm through, which corresponds to OIII emission lines, blocking out all other light. Adding the ZWO O-III Narrowband filter to your imaging collection will help you go beyond the RGB imaging and will help capture your favorite nebulas in a totally new light, no matter how polluted your skies may be!
The ZWO SII 7nm Narrowband Filter passes light at 672nm wavelength with a bandpass of 7nm which is designed for nebula observation. It is suitable for visual observation on most emission nebulae, planetary nebulae and supernova remnants, use it with H-alpha and OIII narrowband filters (SHO Set) for tricolor CCD astrophotography.
Narrowband filter does not eliminate the effects of light pollution or increase the object’s brightness. In many cases, they increase the contrast between nebula and night sky, not brightening the nebula.
It 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).
New vs Old Filters
New Ha filter is based on the new base glass, less reflection( less halo of bright stars).
We made a test of our Ha Filters (ASI1600 mono camera, single frame, 300s, DDP in MaximDL) :
New OIII filter is based on the same base glass, new coating standard, better block rate of off-band.
New SII filter is based on the new base glass, less reflection( less halo of bright stars).