Outsmart light pollution with the Optolong L-eXtreme Filter.

The L-eXtreme Filter by Optolong is a dual band filter that acts against light pollution. It isolates H-Alpha (Red) and O-III (green/blue) nebulae emission lines to improve contrast and maximise nebulae signal.

It works well as a light pollution filter to make the sky darker in urban areas, or even when the moon is out, as there is no transmission between the Ha and OIII lines.

Features

- Maximised transmission of the Ha (656nm) and OIII (496nm / 500nm) main nebula emission lines

- Blocks light pollution from natural skyglow (atmospheric neutral oxygen emission), as well as artificial pollution from mercury vapour lamps and low and high pressure sodium vapour

- Designed for astrophotography through colour cameras and DSLR's in urban areas or areas with heavy light pollution

- Anti-reflective, multi-layered coating

- Integrated IR/UV-Cut Filter

- 7nm bandpass

- High-quality cell made of a CNC machined aerometal

- Includes a polypropylene case lined with a high pressure EVA Case Lining

Please note that the L-Extreme Filter only works with telescopes slower than F4. It will not be compatible with telescopes faster than F4 such as RASAs or Hyperstars.    

Wavelength Spectrum

Warning: Optolong L-Extreme Filters are not suitable for solar viewing. Do not use it to view the Sun. 

Recommended Accessories

	ZWO 7 Position 2-inch Electronic Filter Wheel	Automate your filter swapping with an electronic filter wheel. This filter wheel accepts 7 2" filters.
	ZWO Filter Drawer for T2 Connection	Swap out your 2" filter with ease with a ZWO Filter Drawer for T2 Connection. Suitable for APS-C and smaller cameras.
	ZWO M54 Filter Drawer	Swap out your 2" filter with ease with a ZWO M54 Filter Drawer. Suitable for Full Frame cameras.

About Optolong Optics

Optolong Optics produces a range of specialist narrowband and broadband filters for astronomers of all levels - from amateur astronomers to professional astrophotographers. Whether you are looking for a CLS light filter to reduce skyglow in your backyard or their specialty bandpass filters for deep sky imaging, you’re at the right place.

Product Code: OPT-14801