A polarising filter is a popular accessory in photography that can provide many benefits, particularly when shooting outdoor scenes. This type of filter is designed to reduce glare and reflections from non-metallic surfaces such as water or glass, making it ideal for landscape, nature, and architectural photography. 

By cutting down on unwanted reflections, a polarising filter can improve the clarity and contrast of an image, resulting in a more pleasing and balanced composition. The filter can also help to deepen the color saturation of the sky and foliage, enhancing the vibrancy of the image. Additionally, a polarising filter can reduce the amount of light entering the camera by up to 1-2 stops, which can be useful for shooting in bright conditions or when working with slower shutter speeds. 

Overall, using a polarising filter can help to improve the quality of outdoor photography, producing images that are sharper, more vivid, and more visually appealing.