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).

From 2018, ZWO Made progress on narrowband filters with the new standard, providing better performance.

ZWO New narrowband 1.25″ filter

Technical Parameter

Name: ZWO New narrowband 1.25″ filter

Size: 1.25″

Thickness: 5.5mm+2.5mm(thread)

Glass thickness: 1.85mm

Thread: M28.5*0.6 male thread

Technical Parameter

Name: ZWO narrowband 31mm filter

Size: D=31mm

Thickness: 2mm

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

New OIII filter:

Both side will be fine.

全新窄頻 1.25 吋濾波器

技術參數

尺寸：1.25英寸

厚度：5.5mm+2.5mm（螺紋）

玻璃厚度：1.85mm

螺紋：M28.5*0.6外螺紋

我們對我們的 Ha 濾鏡（ASI1600 單色相機，單幀，300s，MaximDL 中的 DDP）進行了測試：

narrowband 1.25″ filter

Technical Parameter

Size: 1.25″

Thickness: 5.5mm+2.5mm(thread)

Glass thickness: 1.85mm

Thread: M28.5*0.6 male thread