Hard vs Soft vs Reverse

GND Filters or Graduated Neutral Density Filters are available in Hard, Soft and Reverse.

Cameras see the world differently in comparison with the perception of human eye. The light sensation of the human eye is much stronger and we can easily see light and dark areas clearly. However the light sensitisation of our cameras is much weaker. Cameras cannot expose the details of extremely low light and dark scenes at the same time. In order to avoid the loss of any detail (in the lights or the darks), photographers use GND Filters to reduce the exposure of the bright parts, which can balance the bright and dark parts of a scene.

Hard GND Filter

Usually defined by a obvious boundary between the bright and dark area of the scene. They are therefore used when the separation between the bright and the dark areas of the scene is very defined, such as the horizon line or the boundary between sea level and the sky.

Soft GND Filter

Usually defined by no obvious transition between the bright and dark area of the scene. Soft GNDs are therefore used where the transition between light and dark areas is not so clear. An example is a shot in a mountainous area, or trees etc.