The graduated ND10 balances exposure between the lightest and darkest areas of a scene allowing better tone and detail to be recorded in these areas of the image. 

The Hoya graduated ND10 10 is darker at the top giving that area a 3-stop light reduction and then fading evenly to a 1 stop light reduction at the bottom. This creates more balanced exposure between the lighter and darker areas of a scene, especially useful for photos that include the sky. The aluminum filter frame rotates so the darkest area can be positioned as needed. 

The Hoya graduated ND10 10 filter uses a Hoya super clear optical glass in a wedge layer that is matched and perfectly bonded to a ND filter glass wedge layer to create the gradual ND effect. 

Neutral density filters are designed to reduce the amount of light entering your camera lens and do not have any other effect on the image. Reducing the amount of light allows for the use of wider apertures or slower shutter speeds for creative and dramatic affect in bright lighting conditions.