What Is an ND Filter? And How to Use One

Updated: Nov 30, 2019

If you want to use long shutter speeds to smooth out the water or the sky in a landscape photograph, you’ll need a way to darken your lens.The best way to do this is an ND (Neutral Density) filter.

What Is a Neutral Density Filter?

A neutral density filter (ND filter) is designed to reduce the amount of light getting into the lens. The task of an ND filter is to darken your image, so you can use wide apertures or slow shutter speeds.

You can use a neutral density filter (ND filter) for a ton of creative purposes and improving the quality of your photos or videos.

What Can You Use an ND Filter For?


ND filters are traditionally a tool of filmmakers.

To capture the nicest looking video possible, you want to have motion blur, but not too much. A great rule of thumb is to use a shutter angle of 180°. This means that your shutter speed is roughly half of your frame rate.

For example, if you’re shooting a clip in 25fps, your shutter speed should be 1/50s. If you’re shooting in 120fps for slow-motion purposes, your shutter speed should be 1/250s.

If you are a determined video creator, your aperture is locked as well. You don’t want to give up the shallow depth of field.