okay, thanks for the responses. The whole of the area that i live in is lit the same and the main source of light pollution is the LPS streetlights. I've seen the nonad stuff before but am not sure where to get a filter like this from? I've also been recommended a Neodymium filter, as this apparently has excellent blocking of LPS. I quite fancy the idea of darkening the background and enhancing what i'm looking at, i thought that cutting out the light from the streetlights would do this? maybe i'm completely wrong?