A graduated filter is a filter that is dark on one part and clear on the other, with a gradual change between them. The most common type is the graduated neutral density filter, often called an ND grad. It darkens without changing colors.
Photographers usually place the dark part over a bright sky and the clear part over a darker foreground. This balances the brightness of the scene, so the camera can record detail in both areas. It is most often used in landscape photography. Filters with a sharp change are called hard grads, and those with a smooth change are called soft grads.
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