OPTOLONG 2" UHC Nebula Filter Telescope Eyepiece Filter Cuts Light Pollution Planetary Photography

Specifications Size2 InchThickness2 0mmSurface Quality60 40 Refer to MIL O 13830 Fine optically polishedEnsure accurate 1 4 wavefront and 30 seconds parallelism over the both surfacesTransmission90 ThreadM48 0 75Features Suitable for visual observation on most emission nebulae planetary nebulae and supernova remnants Suitable for viewing on bright nebulae like M42 Orion Nebula in heavy light pollution Use with a large aperture telescope under clear and dark viewing conditions with good seeing 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 The Major Emission Lines of Nebulae H β486 1nm OIII 495 9nm OIII 500 7nm H α656 3nmThe Major Emission Lines of Artificial Light Pollution Hg 435 8nm 546 1nm 577nm 578 1nmNa 598nm 589 6nm 615 4nm 616 1nmPackage includes 1 x OPTOLONG filterWARNING 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