Optolong L-eXtreme 1.25″ dual-band astronomy narrow band filter

1.  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.

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.

2.Spectrum and Characteristic

• 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