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Optolong L-eXtreme Dual-band Filter - 2-inch

SKU : OL-L-EXTREME-2

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  • Dual-band light pollution filter - 2-inch.
  • The L-eXtreme filter is dual-band that passes H-alpha and O-iii emission lines.
  • It isolates these two nebula emission lines so that the contrast and signal-to-noise ratio between nebulae were maximized.
  • These two elements (Hydrogen and Oxygen) factor greatly in the scientific exploration of life.

Product Details

  • Dual-band light pollution filter - 2-inch

    The advantage of the L-eXtreme filter is that there is no transmission between the H-beta and OIII lines and there are also no nebula emission lines there. In this case, it isn't letting light pollution come through so it maximizes nebula signals and the sky background is made darker while imaging.

    The L-eXtreme filter should better isolate the emission lines and better protect from light pollution.

    L-eXtreme Introduction

    Optolong 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 nebula, even in bright, light pollution skies. Optolong believes the design of L-eXtreme filter would be a better choice for fast systems at a 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 are living in very light-polluted areas, or when the moon is out, the L-eXtreme will be a good filter.

    Unlike the L-eNhance filter which is a tri-band (transmits H-b, H-a, and O-iii), the L-eXtreme filter is dual-band that passes H-a and O-iii emission lines.

    Comparison of transmission lines of L-eXtreme, L-eNhance, and L-Pro:

    Optolong L-eXtreme Dual-band Filter - 2-inch-transmission-01

    Optolong L-eXtreme Dual-band Filter - 2-inch-transmission-02

    Optolong L-eXtreme Dual-band Filter - 2-inch-transmission-03

    You can also view this charts in greater detail in the Gallery tab, click on the thumbnails for each image.

    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 for the exploration of life.

    Therefore, Optolong highlights H-a, H-b, O-iii, and O-ii, and reduce the signal of sulfur.

    Spectrum and Characteristic

    • Substrate: B270.
    • Thickness: 1.85mm.
    • FWHM: O37nm+Ha 7nm.
    • Blocking range: 300 to 1000nm.
    • Blocking depth: light pollution line blocking >99%.
    • Surface quality: 60/40.
    • Transmitted Wavefront RMS: λ/4.
    • Parallelism: 30s.

     

  • specifications

    BandpassMulti Bandpass
    Filter ShapeRound
    Filter Size2"
    Filter Thickness1.85mm
    Filter TypeDual Band
    Filter TypeLight Pollution/City Light Suppression
    Free ShippingYes
  • included items

    • Dual-band light pollution filter - 2-inch.
    • The L-eXtreme filter is dual-band that passes H-alpha and O-iii emission lines.
    • It isolates these two nebula emission lines so that the contrast and signal-to-noise ratio between nebulae were maximized.
    • These two elements (Hydrogen and Oxygen) factor greatly in the scientific exploration of life.

Product Reviews

Customer Reviews
4.9 Based on 21 Reviews
5 ★
90% 
19
4 ★
10% 
2
3 ★
0% 
0
2 ★
0% 
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1 ★
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  • filter
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  • Bortle 7
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MS
01/06/2022
Mark S.
United States United States

This thing is just amazing

I’ve been at it for about six months and I couldn’t figure out how to capture nebulae without blowing out stars. I felt like I should be getting much better pics from my ASI294 MC-Pro and Apertura 60mm Doublet. Then I got this filter. Attached is my first pic (30 x 5 minutes) of the Flsme Nebula with horrible light pollution.

OPT Telescopes Optolong L-eXtreme Dual-band Filter - 2-inch Review
GT
12/13/2021
Grant T.
United States United States

Optolong L-Extreme Goodness!

This filter has transformed how I work, letting me shoot during moon cycles and in town. I'm using it with a Samyang 135 and DSLR, and it has worked great on my heart and soul images, the first I tried with it. Nebulosity is noticeably enhanced and stars are greatly reduced.

BD
12/09/2021
Bryan D.
United States United States

YUSSS!

My wife bought me a 2" L-eXtreme for my birthday and I just used it for the first time. Ten hours of data over 4 days with an old SBIG STF-8300C in Bortle 4/5 skies with 10 minute subs. I'm thoroughly impressed - it's like I'm at a dark sky site.

OPT Telescopes Optolong L-eXtreme Dual-band Filter - 2-inch Review
SC
12/04/2021
Sherwin C.
United States United States

Optolong L Extreme Dual Band Filter - 2 inch

I live in a Bortle 7/8 zone and this made a huge difference in bringing out the nebulosity for my deep sky objects. Can’t wait to get the newly released Optolong L Ultimate!

DD
11/23/2021
David D.
United States United States

Nice filter

Since I use a bahtinov mask, focusing was more difficult so I now use the optolong clear focusing filter then slide my L Extreme in. Stars are very tiny in finished image!!! Using this with WO Z61 and Sony A6000 modded camera.

OPT Telescopes Optolong L-eXtreme Dual-band Filter - 2-inch Review
WH
11/16/2021
William H.
United States United States

Optolong L-eXtreme

To be completely honest, I was absolutely amazed at the difference this filter made when imaging nebula’s. For example the heart nebula was nearly obscured by the stars, with the filter it was amazing the detail in the nebula and the background was very clean. It works and it’s worth the money!

OPT Telescopes Optolong L-eXtreme Dual-band Filter - 2-inch Review