Optolong L-eXtreme Dual Band 1.25 Nebula Filter
Optolong L-eXtreme Dual Band 1.25 Nebula Filter
Features
1.25" low-profile filter cell suitable for filter drawers, filter wheels - with 1,25" filter thread
The filter has a very narrow bandwidth of only 7 nm for O-III and H-Alpha and provides a very high contrast
The areas of light pollution are completely blocked, so successful deep-sky photography is also possible from close to the city
The filter is suitable for mono and color cameras
H-Alpha regions, but also planetary nebulae can be photographed even at full moon
L-eXtreme Introduction
L-eXtreme is a two 7nm bandpass filter which can be used with one-shot color cameras like DSLR's (digital SLR), and monochrome CCD cameras, it is also more suited for fast systems. The convenience and cost effectiveness of this filter allows amateurs to image a rich emission nebulas, even in bright, light pollution skies. Optolong believes the design of L-eXtreme filter would be better choice for fast systems in competitive price. It isolates the H-Alpha, and Oxygen III nebula emission lines so that the contrast and signal-to-noise ratio between nebulae were maximized. For people who is living in very light polluted areas, or when the moon is out, the L-eXtreme will be a good filter.
Unlike the Optolong L-eNhance filter which is a tri-band (transmits Hb, Ha, and OIII), the L-eXtreme filter is dual band that passes Ha and OIII emission lines.The advantage of the L-eXtreme filter is that there is no transmission between the H-beta and OIII lines, as there is no nebula emission lines there. In this case, it isn't letting light pollution come through so that maximize nebulas signal and make the sky background darker while imaging. The L-eXtreme filter should better isolate the emission lines only and better protect from light pollution.
L-eXtreme Specification
Substrate: B270
Thickness: 1.85mm
Tpeak: T>90%
Blocking range: 300-1000nm
Blocking depth: light pollution line blocking >99%
Surface quality: 60/40
Transmitted Wavefront RMS: λ/4
Parallelism: 30s
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.
