The ZWO narrowband S-II 7nm 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.
- Hubble look of images can be made by the combination of H-alpha, OIII-CCD and SII-CCD, such as the famous “Pillars of Creation” (M16 Eagle Nebula)
- Narrowband imaging with SHO set (H-alpha, OIII-CCD and SII-CCD) can be done with the moon up in heavy light pollution, so your equipment is not sitting dormant for several weeks
- Glass Thickness 2.0+/-0.03 mm (1.25”/31mm/36mm)
- Fine-optically polished to ensure accurate 1/4 wavefront over the both surfaces
- About 90% transmission at SII line 672nm (SII filter )
- Infrared wavelength 700-1100nm cut-off
- <0.1% transmission of off-band, OD3(Optical Density)