I shot this with my new screw-in Sigma DG polariser. It's the first time I've had a screw-in as all my lenses now have the same thread (77mm). Otherwise it's too expensive to have different filters. It was cloudy in this shot so not much polarising of the sky, but it works really well at bringing out nice soft colours. A good filter, but not cheap at £110. Haven't told the wife yet.