Pollution filter & M27 (Dumbell Nebula)

I was curious to see how effective a light pollution filter would work on Milton Keynes skies so yet more spending on an Astronomik CLS filter which seemed to get many recommendations. I obtained the "in camera" version as it would work with my normal camera lenses. Initial tests seemed to indicate that at least twice the exposure was needed than without the filter to obtain similar detail. I wasn't sure what to expect and replacing the red tinge with a greeny blue one didn't feel like much of a step forward when I tried using it on M27. A quick test on M31 definitely didn't bring any benefits and I was much happier not using it on the Andromeda galaxy. I guess this will be better on some objects than others so a bit of learning obviously required. Here is the result on M27 which was 12x 120second exposures@iso400(images only) in Deep Sky Stacker & CS2 (click for larger version)

No comments: