Whether they are solid (ND) or graduated (GND), neutral density filters reduce the amount of light that reaches the sensor, on the whole image or partially depending on the filter. They emphasize the flow of movement, reduce the depth of field, and avoid overexposure. They are also useful in video to maintain constant shutter speed and optimize bokeh capabilities with bright lenses.

The circular and linear polarizing filters optimize color saturation, enhance contrast and give the sky a typical dark blue hue. They also remove non-metallic surface reflections. It is impossible to reproduce a polarizing effect with image processing software.

Some colored filters are still widely used by photographers working in Black & White. In both film and digital, they have a strong effect on tone, saturation and contrast, depending on how you capture black & white images. This category also includes infrared filter and its unique possibilities.

Conversion filters help rectify strong color temperature variations. Lighter density versions of these blue or orange filters apply subtile color temperature corrections that reduce or eliminate dominant tones.

When the sky is not as blue as you wish, when the sunset is not vibrant enough or if you would like to add a personal color touch, the graduated colors are the ideal choice. They darken a part of the image (generally the top part) by adding a color: blue, tobacco, emerald, sunset, etc.