elements in the picture, such as moving animals (especially birds), people or vehicles. It can also be a problem if the environment is kinetic (in motion), such as wind blowing and shaking all the trees and plants in the scene, or if water is flowing. Slow shutter speeds can also be a problem if the photographer is in motion (such as shooting a scene from a moving vehicle). Consequently, some compromise between shutter speed and aperture may be necessary, or advisable. To some extent, a higher-ISO film or digital camera setting can compensate without the need to alter shutter speed or aperture. However, higher ISO settings ("fast film") can result in grainy pictures and poor capture of details, especially at a distance. In some cases, a slow shutter speed is desired to show movement of the subjects, particularly moving water or the effects of wind. Filters Filters can serve a wide range of purposes in landscape photography. For instance, a polarizing filter can darken the sky, while allowing surface features to be shown in relatively sharper clarity. Polarizing filters also help with cutting glare from water reducing reflections, snow and ice—even facilitating greater transparency of water and ice. Neutral density filters are darkened with a neutral (colorless) gray tint which reduces the amount of light entering the camera lens. These filters are used to lengthen shutter speeds without the need to alter aperture or film/sensor sensitivity, or alternatively, to use large apertures without exceeding the maximum shutter speed of a camera. A variation of this filter, termed the graduated neutral density filter or simply 'ND grad', transitions from dark, neutral gray on one side to clear on the opposite side. Photographers use these filters to lower natural contrasts by reducing light transmission from the brightest portion of the subject landscape, while letting light from the darker portion of the landscape enter the lens unobstructed. UV-Zero haze filters reduce "purple fringing" caused by ultraviolet light, especially in digital situations. They are also recommended by some professional photographers as protection for the vulnerable lens, especially when outdoors or in dynamic situations. Color filters can create other effects, or compensate for the appearance of unnatural lighting due to camera characteristics. Other accommodations In order to mitigate shaking associated with hand-holding a camera, landscape photography oftentimes requires a firm camera footing which affords the potential for sharper imagery. Tripods are specifically designed for stabilizing