Simple stuff if you already know how to use a polarising filter but if you don’t as was the case with me when I first found this video, this will help.
A polarising filter can darken a sky and saturate colour by removing glare. But a polarising filter only works when you’ve got some direct light coming in from the side. Ideally at about 45 degrees to the lens. I spent a a day filming with ace landscape photographer Tom Mackie and asked him to show us more because he’s an expert. Polarising filters can be used in all kinds of photography but it’s fair to say they come into their own when shooting landscape. As you turn the filter you can see the effect happening through the cameras viewfinder. But be cautious because it can be easy to over do it and make your photos look a bit un natural. Another thing to remember is that a polariser removes about two stops of light so DON’T leave it on your lens all the time because you’ll end up with slower shutter speeds and possibly fuzzy pictures caused by camera shake. However they can be handy if you want to remove some light to get a slow shutter for a motion blur effect. – Mike Browne