I finally got my hands on an Astronomik CLS CCD light pollution filter! Ive been trying to get my hands on one of these for quite some time now. They are rarely in stock at the few US retailers that distribute them.
There are comparable filters available, though Ive heard they are inferior and lacking. That manufacturer is Optolong, but please do not read this as a review of their products. In fact their filters may be better than Astronomik’s. I have not read this though and set my sights on the Astronomik CLS CCD.
Unfortunately 90% of the “light pollution” filters being sold today are far from what they claim to be. Most do nothing more than increase contrast and decrease light from throughout the entire visible spectrum, actually leading to additional issues as far as astrophotography is concerned.
The Astronomik light pollution filter on the other hand literally notches out undesirable light emissions signatures from sodium and Mercury vapor industrial lights, like 90% of street lights. These filters leave open important signatures like those from emission nebula and supernova remnants.
Anyway the following image is of the Great Orion Nebula, M42 captured using the Astronomik CLS CCD in front of a modified Canon 70D sensor. The image is an integration of 20 something sub frames which have been stacked in Deep Sky Stacker and processed in Photoshop.
If you’s like check out earlier images of M42 that I have posted here. The difference is really stunning in all aspects.