OPTOLONG 3nm NARROWBAND SHO FILTER SET

The NEW Optolong 3nm H-Alpha, Oxygen-III and Sulphur-II narrow-band filters boost the contrast of emission nebulae and supernova remnants for professional results, even under a bright sky affected by light pollution. This filter is used in combination with the OIII and SII filter to compose a narrowband colour image.

The 3nm band pass is only 1% of the entire visible spectrum, increasing the signal to noise ratio and delivering high contrast images and extremely dark backgrounds.

The high transmission and off-band blocking maximize contrast and minimise the halos around bright stars.

The filter cuts off the ultraviolet and infrared light so there is no need to use the IR-cut filter.

Every Optolong filter is marked with its unique serial number and individual passing band certificate. This test is rarely provided by any producer and it is a standard for high quality filters.

 IC1848 by Mickey | GSO RC10, ZWO ASI6200MM, Optolong 3nm H-alpha, OIII & SII.

The interferential coating is deposited on the substrate using electron-beam gun evaporation with ion-assisted deposition coating technology. This increases the filter durability and resistance to scratching, as well as stability of the CWL (central wavelength). The planetary rotation system offers precision and homogeneity of the coatings ensuring high transmission of the pass-band and high optical density off-band.

WARNING: Optolong filters are not designed for sun observations. DO NOT LOOK AT THE SUN WITH OPTOLONG FILTERS. You could become BLIND if you fail to observe the warning.

NGC7000 by Tommaso Massimo Stella under Bortle 9 skies | Takahashi FS-60CB + Reducer 0.72x, QHY 168C, Optolong 3nm H-alpha, OIII & SII.