Brand: Optolong

Optolong L-eXtreme Dual-Band Narrow Band Filter 2" Mounted (OPT-L-EXTREME-2)


Brand: Optolong

Optolong L-eXtreme Dual-Band Narrow Band Filter 2" Mounted (OPT-L-EXTREME-2)


$309.00 USD

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$309.00 USD

Easy Payment Options with .

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Product Description

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.

Hydrogen is the largest, the most primitive, the simplest, and the oldest element in the universe. Scientists consider that Hydrogen amounts to more than 90% of visible substance in space. Our sun is 5 billion years old, but so far hydrogen is still the key matter of nuclear fusion. While the sulfur element does not have much scientific significance, so keeping H and O is meaning for exploration of life.
Therefore, we highlight H-a, H-b, O3 and O2, and reduce the signal of sulfur.

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

Coating Technology

  • Multi-layers anti-reflection coating
  • Non-cementing optical substrate coating
  • Optolong L-Pro filter adopts precision coating based on Ion-assisted deposition coating technology for durability and resistance to scratching, as well as stability on CWL(central wavelength) no deviation affected by temperature change.
  • Planetary rotation system offers precision and homogeneity of coatings ensuring high value on transmission of pass-band and Optical density of off-band.

Warm Prompt

  • About colour: due to the influence of ambient light, colour difference of the display and flash photography, the colour of the product may have some colour difference. Detailed colour is in accordance with the final product.
  • About coating: the interference filter will show different colours under different light, which is a normal phenomenon. Please refer to the material object.
  • About the style: in order to improve the product, the change of design/appearance/parameters has not been updated in time. Please see the subject produce.
  • About the description: the series of this product have the same material, technology and design, different sizes only, please note.

Customer Reviews

Based on 5 reviews
Optolong L-eXtreme

Works well but I've noticed some halos around bright stars.

Great filter for light polluted skies

This filter, coupled with a fully modified mirrorless camera has allowed me to image things such as the eagle nebula from by bortle 7 back yard looking directly into the light dome of my city. 15 mins of exposure time reveals more than I thought possible. Very happy with the filter, and as always, All Star's quick delivery, and great service. Thank you guys!

Great filter for shooting narrowband in the city!

I ordered online, it was shipped the next business day and I received it as expected 2 days later! Great product, great service!

Solar Photography

With all the sunny Alberta days, I wanted to try to take pictures of our sun with one of my travel setups. I used a RedCat 51 with a ZWO ASI294MC Pro with a clear filter. Tracking was with a Star Adventurer.

I finally got a clear night t

I finally got a clear night to do first light with this filter. So far the results look great. But the best part was the amazing service and a quick delivery time and the ability to deal with a local company that cares about customer service.

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