What is a Neutral Density Filter and How to Use it for Photography

June 22, 2023 12:17 PM by Isaias J | Discover

An ND filter is a type of camera filter that you can put on your camera. They stand for Neutral Density Filter. The name derives from the ability for light to be spread through a visible spectrum of light.

Explanation

Simple: ND filters lower the amount of light to your camera allowing you to use slower shutter speeds, iso or aperature to obtain special effects on your camera.

ND filters lower the total amount of light a camera is able to receive due to the properties of the density of the light. The density affects the way light is received by your camera.

Some examples of using ND Filters include long exposure, light trails, video and cinema filtering, harsh light filtering.

Photography with Neutral Density Filters

Scenario one: Capturing Light Trails and Water

Using a ND filter can allow you to increase your camera’s shutter speed on the exposure triangle. For example putting on a ND filter of +1 will give you an arbitrary exposure of f8 3s iso 100. Putting a denser (higher numbered) ND filter such as +2 will give you an arbitrary exposure of f8 6s iso 100. And on and on…

This may allow you to capture certain environments that without the ND filter you would get something like f8 1/10s iso 100 which would be a faster shutter speed. Finally to end it off with the extreme, think of a ND filter with +5, your exposure may be something close to f8 11s iso 100.

Cosmetic effects include light trails, silky water streams, fireworks and more.

Scenario two: A Sunny Bright Day

They can also be used to create a restriction on changing other settings on your camera like the aperture or shutter speed. An example is during a bright sunny day. Often you will have to use your camera’s extreme shutter to combat the amount of light that comes to your camera. Say a “perfectly lit” exposure is f8 1/800s 100 iso. Let's say for artistic effect you would like a slower shutter speed. Put on an ND filter of +6. Now your exposure is f8 1/200s 100 iso. Here you can imagine the usefulness of having ND filters.

Taking another example imagine you are taking close up depth photographs where you require blur in the background and it’s sunny outside. Let's say your aperture must be f1.2. Similar to the last situation, the sunny day will encourage you to boost your shutter speed. However you don’t want to shoot at 1/1000 or higher. Put on an ND filter and you can lower your shutter speed in this case. It’s noted that the iso remains at 100.

ND Filter Strength

Now that we know what Neutral density filters are we will get into the various strength and densities by different ND filter numbers like ND2, ND4 , ND8, ND16.

ND2 reduces the amount of light entering the lens by one full stop. Only 50% of the original light is shown through the camera.

ND4 reduces the amount of light entering the lens by two full stops. Only 25% of the original light is shown through the camera. This allows you to use slower shutter speeds.

ND8 decreases the light that enters the lens by three full stops. Only 6.25% of the original light passes through.

ND32 and beyond show even more light reduction. One caveat to using higher ND filter sizes is the loss of color that may occur. The ND filter may come with their own “hue” often bluer than the original light.

Additional uses of ND Filters

Landscape Photography: Using ND filters in landscape photography can significantly enhance your images by allowing you to control exposure, create motion blur effects, and balance the exposure between the sky and the foreground.

Skyline Photography: Using ND filters for skyline photography can help you capture well-balanced exposures, smooth out motion, and enhance the overall image quality.

Long Exposure Photography: Using ND filters for long exposure photography allows you to create stunning effects such as silky smooth waterfalls, streaking clouds, or the elimination of moving objects.

Cinematography and Filmmaking: Using ND filters in cinematography and filmmaking is a common technique to control the exposure and achieve specific creative effects.

Conclusion

An ND filter, short for Neutral Density filter, is a camera filter that reduces the amount of light entering the camera. It allows for the use of slower shutter speeds and enables photographers to achieve various special effects. ND filters are commonly used in scenarios such as capturing light trails and water, dealing with bright sunny days, and creating cosmetic effects like silky water streams and light trails. They help control exposure, create motion blur effects, balance exposure in landscape and skyline photography, enable long exposure photography, and are frequently employed in cinematography and filmmaking. ND filters come in different strengths and densities, such as ND2, ND4, ND8, and higher, each reducing the light entering the lens by a specific number of stops. However, using higher ND filters may result in a loss of color or introduce a bluish hue to the images. Overall, ND filters are versatile tools for photographers and videographers to enhance their creative vision and achieve desired visual effects.