ZWO 1.25" OIII 7nm Narrowband Filter - OIII7nm125

The ZWO narrowband OIII 7nm filter is designed for nebula observation by allowing a 7nm bandwidth of light to be centered on a wavelength of 500nm (which corresponds to OIII emission lines), and blocking out all other light.  Adding the ZWO OIII Narrowband filter to your imaging collection will help you go beyond RGB imaging and will help capture your favorite nebulas in a new light, no matter how polluted your skies may be!

This rendition of the ZWO OIII 7nm Filter is housed in a 1.25" threaded metal cell and can be used in 1.25" filter wheels or the ZWO 2" filter drawer with a 2" to 1.25" filter adapter installed.  

How to Use the ZWO OIII 7nm 1.25" Filter...

• A Hubble look 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 in the sky so your equipment is not sitting dormant until the next new moon.

Specifications

• Size: 1.25″

• Thickness: 5.5mm + 2.5mm(thread)

• Glass thickness: 1.85mm

• Thread: M28.5*0.6 male thread

• FWHM：7±0.5nm

• Fine-optically polished to ensure accurate 1/4 wavefront  over the both surfaces

• About 90% transmission at major OIII line 500nm

• Infrared wavelength 700-1100nm cut-off

• <0.1% transmission of off-band, OD3 (Optical Density)