Dual H-Alpha/O-III 7nm narrowband filter Allows for imaging in bright man-made light pollution and moonlit conditions Most useful for One-Shot Color cameras Take color images without needing to combine images with multiple filters Use for taking images of emission nebulae The Optolong L-eXtreme is a 7nm dual-bandpass filter which can be used with one-shot color cameras like DSLRs and CCD/CMOS astrophotography cameras. It is also more suited for fast systems. The convenience and cost effectiveness of this filter allows amateurs to image emission nebulae even in bright, light-polluted or moonlit skies. The L-eXtreme isolates the H-Alpha and Oxygen III nebula emission lines so that the contrast and signal-to-noise ratio of the nebulae are maximized. For people who are imaging in very light polluted areas or when the moon is out, the L-eXtreme is an excellent choice. The advantage of the L-eXtreme filter is that there is no light transmission between the H-beta and OIII lines (as there are no nebula emission lines there). This reduction in light pollution maximizes the nebula's signal and makes the sky background darker while imaging. Unlike the L-eNhance filter, which is a tri-band (transmits Hb, Ha, and OIII), the L-eXtreme filter is dual-band, passing just the Ha and OIII emission lines in order to deliver improved light pollution rejection. Note: For imaging galaxies and reflection nebulae, the Optolong L-Pro filter is more appropriate as this filter will reject much of the light from those objects.