Narrowband OIII filter is designed for nebula observation allowing 18nm bandwidth of light centered on a wavelength of 500nm through, which corresponds to OIII emission lines, and reducing 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.
|Size||1.25'' 18nm O-III|
|Transmittance||90% at 495.9nm and 500.7nm|
1. Svbony narrowband OIII filter suitable for visual observation on most emission nebulae, planetary nebulae and supermova surfaces
2. Suitable for viewing on bright nebulae like M42 Orion Nebula in heavy light pollution
3. Use with a large aperture telescope under clear and dark viewing conditions with good seeing
4. Narrowband filter do not eliminate the effects of light pollution or increase the object's brightness. In many cases, they increase the contrast between nebula and night sky, not brightening the nebula