Free Shipping On Many Items

The Telescope Authority
Since 1947

View Shopping Cart

Your Cart is Empty

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

SKU : OL-L-EXTREME-2

- Read
  • Free Shipping

  • In Stock

Add to Wishlist

Got questions? Click for live chat

  • 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 18 Reviews
5 ★
89% 
16
4 ★
11% 
2
3 ★
0% 
0
2 ★
0% 
0
1 ★
0% 
0
Customer Photos
Write a Review Ask a Question

Thank you for submitting a review!

Your input is very much appreciated. Share it with your friends so they can enjoy it too!

Filter Reviews:
  • filter
  • skies
  • light pollution
  • results
  • Moon
  • imaging
  • design
  • performance
  • money
  • exposure
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
RN
10/12/2021
Ryan N.
United States United States

Amazing Filter!

Before using this filter I used to always have to push the color saturation in my images but not anymore. I haven't boosted color saturation at all with filter, the colors already come out so vivid! The design of this filter is great. I have a RedCat, which was super easy to mount this filter onto, just screws right in. Just required a little change in focus and I was off and imaging.

OPT Telescopes Optolong L-eXtreme Dual-band Filter - 2-inch ReviewOPT Telescopes Optolong L-eXtreme Dual-band Filter - 2-inch Review
RS
10/11/2021
Richard S.
United States United States

Made narrowband work so much easier

I had started out with separate Ha and OIII filters for use with my One Shot Color camera, but quickly tired of the extra exposure time and nuisance of aligning images. Also the overall cost of the separate filters was more than the expense of the single dual narrowband L-eXtreme filter. Wished I hadn't wasted the money and just bought the L-eXtreme filter in the first place!

OPT Telescopes Optolong L-eXtreme Dual-band Filter - 2-inch Review
RB
09/29/2021
Rick B.
United States United States

L-eXtreme Filter

I've had a chance between the clouds to use the L-eXtreme with my Zwo 533 Pro and WO 73. I was very happy with the mages of the heart and soul nebula under 98% moon. 4 minute subs. I'm fortunate to shoot under bortle 1-2 skies. I'm very happy with the results.