A GND filter, or Graduated Neutral Density filter, is a photography accessory used to balance exposure between the bright and dark areas of a scene. It features a gradient that transitions from dark to clear, allowing photographers to reduce the brightness of the sky while keeping the foreground properly exposed. This helps in capturing more detail in both highlights and shadows. GND filters are particularly useful in landscape photography, where the sky is often much brighter than the land. By using a GND filter, photographers can achieve a more balanced image without resorting to complex editing techniques, making it easier to create stunning visuals directly in-camera.