The Optolong CLS CCD Filter - 1.25" is a city light pollution filter used to block artificial light sources that deteriorates the contrast from deep sky imaging. These include light from street lights, mercury vapour lamps, sodium vapour lights and natural skyglow which all affect conrast from emission nebula wavelengths. 

The Optolong CLS CCD Filter then maximises transmission of the main nebula emission lines: OIII, H-beta, NII, H-alpha as well as SII. 

Crafted using a thin metal cell anodised housing, these filters are suitable with most filter wheels. 

• Ultra-thin filter cell to maximise the compatibility with most filter wheels
• Multi-layers anti-reflection coating

For astronomy cameras, it needs to be used in combination with an IR/UV cut filter. Alternatively the CLS-CCD filter can be used as it cuts off the infared and ultraviolet wavelengths. In DSLR the IR/UV filter is embedded in teh camera so the standard CLS filter is sufficient.

Light pollution filters do not eliminate the effects of light pollution or increase the object's brightness. It does increase the contrast between nebulae and night sky.

The Optolong CLS CCD Filters come in 1.25", 2",  and Canon EOS C variations. 

About Optolong

Optolong Optics is a specialist manufacturer of astronomy and astrophotography filters that are adored by astrophotographers worldwide since it was established in 1999. Particularly famous for their bandpass narrowband filters, “L-Pro” , "L-eXtreme" and "L-eNhance” which enables high quality imaging from simple one shot colour cameras, it’s hard to find a serious astrophotographer that has not longed for an Optolong filter in their tool kit. 

Product Code: OPT-11901