Optolong L-eXtreme Filter


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Capture the cosmos with our best light pollution filter, the Optolong L-eXtreme. Boost contrast and signals even under urban skies. Perfect for DSLR and telescope astrophotography, it isolates celestial spectacles while eliminating 99.9% of light pollution.

- Targets H-alpha & OIII emission lines
- Overcomes urban light pollution
- Ideal for DSLR & CCD astrophotography
- Attains 93% transmission, sharp nebula contrast
- L-eXtreme Filter: clarity amplification for celestial captures

L eNhance Filter curve

The Major Emission Lines of Nebulae: H-α 656.3nm, H-β486.1nm, OIII 495.9nm, OIII 500.7nm 
The Major Emission Lines of Artificial Light Pollution: Hg 435.8nm, 546.1nm, 577nm, 578.1nm, Na 598nm, 589.6nm, 615.4nm, 616.1nm

Optolong will continue to optimize the product according to actual testing, therefore the above curve is not to be used as the final product data.

Available Sizes

1.25” mounted and 2” mounted are available now.
Other sizes will be listed when become available.

Sample photos

Object: M42

Time : 15th.--16th. March 2020

Place: HongKong-Shatin

Camera : ZWO ASI183MC Pro

Telescope : f/5 @ Sky-Watcher N130/650 w coma corrector

Filter : Optolong  L-eXtreme 2"

Mount : iOptron CEM25EC

Guide : 120mm mini guide scope, ZWO ASI120MM mini

Light pollution level 7~8(City center, light pollution disaster area

Copyright: ©Vincent Cheng (Hong Kong)


Object:NGC6946, Barnard 150 & Sh2-129 Flying Bat nebula

Equipment:Canon 6D mod+WO SpaceCat 51+Optolong L-eXtreme&L-Pro

Data:RGB 25 x 600" ISO 3200 - Optolong L-Pro

H-Alpha & OIII 20 x 1500" ISO 320 0 - Optolong L-eXtreme

Copyright: ©José Jiménez (Spain)


Package Details 

  • Silver cardboad box
  • Plastic PP box
  • Imported high pressure EVA case lining

Optolong L-eXtreme Filter