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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
4.8 Based on 11 Reviews
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Filter Reviews:
RG
06/29/2021
RICK G.
Excellent filter

Excellent filter in the duo bandpass. Cuts through light pollution and gathers amazing bandwidth from DSO targets. HIGHLY recommend...single 10 minute exposure of the Cygnus loop, Redcat51 with ASI294MC Pro and L-Extreme filter

OPT Telescopes Optolong L-eXtreme Dual-band Filter - 2-inch Review
WC
06/24/2021
William C.
United States United States
No Greasy Filters!

I gave up using this excellent 2"filter in my Radian 61 filter well and had it reset in a Canon Drop-In Filter. Now I can use the filter without greasy finger smears and use in several other lenses.

NV
05/17/2021
Neil v.
South Africa South Africa
My first Astro image.

So I spent almost a year researching and learning the theory behind astrophotography. Finally got the last pieces of the puzzle yesterday in the form of a star tracker and then the universe rewarded my patience with clear skies! So here my very first attempt at astrophotography. Carinae Nebula. Straight from Sequator without any post processing. Bortle 7 zone. Radian Raptor 61 with Optolong l-eXtreme on a Star Adventurer 2i pro. Stock standard Nikon D5100. 30 second exposures at ISO 1600. Just over 1 hour total exposure. The results speak for itself. Definitely worth the price tag!

OPT Telescopes Optolong L-eXtreme Dual-band Filter - 2-inch Review
SP
03/02/2021
Stu P.
New Zealand New Zealand
Nice even in dark skies

I ordered this filter through OPT to be used in conjunction with my colour camera (ASI2600) and canon 6D so I could image during a full moon or in less than ideal conditions due to a sports club nearby which really has a lot of light flowing into the sky on most weekend nights.However, I was really keen to try this out in dark skies as well to see how the Ha performs in a f4.5 system.I was told that I was wasting my money and this only works in very light polluted skies. Even though I had to wait for an age for the filter to arrive that wasn’t OPTs fault but I actually forgot about this filter till one day it turned up in the mail(months later) I paired this with a WO Redcat 51 and ASI2600MC camera on a ioptron GEM45 mount (all purchased at OPT). I have spent a few nights just doing testing and have not completed an image yet.What I have seen so far impresses me and I am looking forward to really getting into some long exposure imaging in the coming months. The sample images below are all 3X15 mins and are only test images.Only simple stretching was done and I overdid that to look at the detail.Please forgive that the ordination was different as the images were done on different nights.I used the L-eXtreme on a full moon night while the no filter images were on a moonless night.The image of the LMC was taken in dark skies. I am happy with the filter and it clearly shows the Ha and OIII data.I am wanting to do more testing in other conditions but for colour cameras, even in dark skies it works well and saves changing to different filters.The major advantage for me is that a full moon night is not wasted. I can highly recommend this filter

OPT Telescopes Optolong L-eXtreme Dual-band Filter - 2-inch ReviewOPT Telescopes Optolong L-eXtreme Dual-band Filter - 2-inch ReviewOPT Telescopes Optolong L-eXtreme Dual-band Filter - 2-inch ReviewOPT Telescopes Optolong L-eXtreme Dual-band Filter - 2-inch ReviewOPT Telescopes Optolong L-eXtreme Dual-band Filter - 2-inch Review
RS
01/01/2021
Robert S.
United States United States
I like this filter

Awesome for light pollution and full moon imaging of emission nebulas.

RM
11/17/2020
Richard M.
United States United States
Outstanding service

Did not use it was Purchased as a gift. I am sure he will love it