ZWO HA 7NM FILTER 36mm

Narrowband filters do not eliminate the effects of light pollution or increase the object’s brightness, but rather increase the contrast between nebula and night sky. 

They 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). 

• The 'Hubble look' can be produced with the combination of H-alpha, OIII-CCD and SII-CCD, as in 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

• A H-alpha filter is the first narrowband addition to an LRGB set for most imagers, who blend a black-and-white Ha image into RGB data to enhance structural detail, while maintaining a natural look

Technical Parameters:

Name: ZWO New narrowband 36mm filter

Size: D=36mm

Thickness: 2mm

The ZWO H-Alpha filter has a bandpass of 7nm and passes light at 656nm wavelength, light transmission rate comes up to 80%. 

Correct Orientation

Note: example uses 1.25" filter

Technical Data

• FWHM：7±0.5nm
• 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 H-alpha line 656nm (H-Alpha filter )
• Infrared wavelength 700-1100nm cut-off
• <0.1% transmission of off-band, OD3 (Optical Density)

Transmission Curve

New Narrowband & Old Narrowband filter:

New Ha filter is on a new glass base, with less reflection (less halo of bright stars).