Optolong O-III CCD 12nm Filter 2" (50mm). OIIICCD12NM2
The narrow-band OIII filter is designed for nebula observation allowing 12nm bandwidth of light with a center wavelength (CWL) of 500nm. This corresponds to OIII transmission lines. It reduces the transmission of certain wavelengths of light, specifically those produced by artificial light. This would include mercury vapor, both high and low pressure sodium vapor lights, and the unwanted natural light caused by neutral oxygen emission in our atmosphere (i.e. skyglow). OIII transmits the wavelengths of 495.9nm and 500.7nm. It is a blue-green colored filter. Many images of planetary nebula and supernova remnants are taken only with the H-alpha and OIII filters. They show great structural detail, have natural colors, and look like an RGB image. Main Use and Performance • Suitable for visual observation of most emission nebulae, planetary nebulae, and supernova remnants. • 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). • Narrow-band filters do not eliminate the effects of light pollution or increase the object’s brightness. In many cases, they increase the contrast between nebula and the night sky, but do not brighten the nebula. • WARNING: Optolong filters are not designed for sun observation. DO NOT LOOK AT THE SUN WITH AN OPTOLONG FILTER. BLINDNESS could occur if you fail to observe this warning.