Last week I received an Astronomik clip in CLS filter for my Canon Rebel. I got it in hopes it will help with the streetlight across the street as well as other local light pollution. I must say, it does take away the muddy brown tint in my images, but it also shifts the color balance on the blue side. However, that can be taken care of by increasing the red slightly in the camera.
Unfortunately the moon has been out, so I really couldnt give it a good test yet. Last night however, I was able to shoot for about 30 minutes or so without the moon interfering. It was enough to notice the absence of the brown gradient. My target was M106. Because the data was rather lacking because I only shot about 45 minutes at iso 400 (5 minute subs), the faint detail really isnt visible. What I am impressed with is the detail in the fainter, tiny galaxies in the image. I am especially impressed with how NGC4217 came out. Thats the little galaxy on the top of this image.