Check the listing for details. OIII-CCD 12nm (Bandpass Photo Filter) 1.25''. Condition: New. Listed at 120.00 USD. OIII-CCD 12nm (Bandpass Photo Filter) 1.25 OIII-CCD 12nm (Bandpass Photo Filter) 1.25 Bandpass Photo Filter OIII-CCD 12nm Narrowband OIII filter is designed for nebula observation allowing 12nm 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 (i.e. skyglow). OIII emits 495.9nm and 500.7nm and it is a blue-green colored filter. Many of images of planetary nebula and supernova remnants are taken only with H-alpha and OIII filters. They show great structural details, but have natural colors, looking like an RGB image. Main Use and Performance Suitable for visual observation on 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) 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. WARNING: The filters of Optolong are not designed for sun observation. DO NOT LOOK AT THE SUN WITH OPTOLONG FILTER. You would be BLIND if you fail to observe the warning. Technical Data Schott substrate material Thickness 2.0mm Surface Quality: 60/40 (Refer to MIL-O-13830) Fine-optically polished to ensure accurate 1/4 wavefront and