I have been using the Astronomik CLS Filter for the last few years to get rid of light pollution in my astrophotos. The filter has done a really good job so far and have given me some good results, specially when doing deep sky astrophotography. I was planning on modifying my Canon 6D for astrophotography, so it is more sensetive to H-alpha. But before I could completely modify my camera, i wanted to give some other astronomik filters a try. Specially the UHC Filter and 12nm Ha Filter as these filters only allow narrow wavelengths (specially the 12nm Halpha.) Below is a comparison for the CLS and UHC transmission chart. As you can see from the above images, UHC filter has a narrow transmission and thus gets rid of any unwanted light (City Lights) The result of shooting through the UHC filter is that you get a better sky contrast hence the name UHC (Ultra High Contrast), The UHC works better on any kind of emission nebula: When a nebula is emitting light only at certain wavelengths, you may block everything else to get a very dark background with a high contrast: That´s the intention of the Astronomik UHC. I […]