Neutral Density Filters Explained

Takako waterfall. vertical picture of a beautiful waterfall.

What is a Neutral Density Filter, and what do you use it for?

A neutral density filter, also known as an ND filter, is a tool used in photography to control the amount of light entering the lens. This allows photographers to adjust elements such as aperture, exposure time, and sensor sensitivity, helping them avoid overexposed images. By using this type of filter, photographers can achieve desired visual effects, such as a shallow depth of field or motion blur, even in challenging lighting conditions. For instance, they can use a slow shutter speed to create a blurred effect on moving subjects. Photographers often employ this technique for artistic purposes. Examples of these applications include:

  • Blurring water motion such as streams and waterfalls.
  • Reducing the depth of field.
  • Add motion blur.
  • Extend the length of the exposure.

To capture the desired milky water effect, one can adjust the shutter speed while photographing a waterfall. A slower shutter speed of five seconds may be necessary to achieve the desired effect. However, on particularly sunny days, even at the smallest aperture setting, the five-second shutter speed may result in overexposure due to excess light entering the camera. To combat this issue, using a neutral density filter can effectively reduce the amount of light entering the camera and allow for longer shutter speeds without overexposing the photo.