OIII 7nm ZWO 36mm unmounted circular filter

The ZWO O-III 7nm narrowband filter is designed for astrophotography, focusing on a wavelength of 500 nm. It can be used in combination with H-Alpha and S-II filters to achieve "Hubble-like" images. By selectively reducing transmitted wavelengths, this filter suppresses the effects of public lighting.

Characteristics

• Wavelength: 500 nm
• FWHM (Full Width at Half Maximum): 7 nm (+/-0.5)
• O-III line transmission: 90%
• Infrared cutoff: 700/1100 nm
• Schott glass with precise optical polishing to ensure a precise wavefront at lambda/4 and parallelism <30" of arc on both surfaces
• Double-sided optical coating with anti-reflection treatment
• CNC-machined aluminum cell construction

Usage

The ZWO O-III 7nm filter is excellent for enhancing the contrast of nebulae in CCD imaging, digital photography (unmodified or modified camera). It is not compatible with visual observation (dark sky or city sky), film photography, webcams/videos (planetary or deep-sky).