What the heck is a neutral density filter? Read below for our simple explanation!

With so many tools and accessories available to photographers, it can be difficult to determine which ones to add to your photography bag. Neutral density filters are a great addition for photographers that shoot in harsh light or want more creative control in-camera. They are a small, but a mighty tool for landscape and portrait photographers! Read on to learn how using neutral density filters can help you take your photography to the next level.

What Are Neutral Density Filters?

Neutral density (ND) filters attach to your lens to reduce the amount of light that enters your camera’s sensor without changing the color of the light. They allow you to achieve long-exposure, motion-blur and shallow depth-of-field images even in harsh light.

They come in a variety of optical density or stop ratings, and allow you to increase your aperture or slow your shutter speed in order to maintain proper exposure even in the harshest lighting conditions. The most common neutral density filters enable you to block out up to nine f-stops of light. If you have ever wondered how another photographer achieved those silky water shots in harsh light, they most likely had an ND filter attached to their lens.

There are two types of ND filters – circular screw-in filters and plate-type square or rectangular ones that fit inside a holder that affixes to the front of your lens. Circular filters are easy to use, as they simply screw onto your lens. The square/rectangular filters require a holder and can be more expensive, but are often a higher quality.

What Are Graduated Neutral Density Filters?

These ND filters have a gradual transition in density, allowing you to properly expose both the foreground and background of an image. The density of the filter becomes gradually darker, allowing you to expose for a darker foreground without blowing out the background. These types of ND filters are most beneficial in landscape photography

Graduated ND filters are also available in circular and square options and with the same varying densities as regular ND filters.

When To Use a Neutral Density Filter.

An ND filter is useful anytime you want to achieve motion blur or a shallow depth-of-field in your images in harsh light. Many landscape photographers use ND filters to capture long-exposure photos in either direct sunlight or the bright white snow of winter. Portrait and sports photographers may also choose to use an ND filter if shooting in broad daylight and need to limit the amount of light entering their camera’s sensor while maintaining proper exposure for their shot.  

Read more about using ND filters at sunset to enhance the colors in your image here.

How To Use a Neutral Density Filter

ND filters either affix directly to your lens (circular) or are placed in a holder that attaches to your lens (square/rectangular). Determine which ND filter you will need to achieve your desired result and securely attached it to your lens. Compose the shot and fire away. Review the image and adjust your settings as necessary.

This chart will help you to determine how to adjust your settings using the various ND filters. For example, the ND64 / ND 1.8 filter allows you to adjust your aperture or shutter speed by six stops. If shooting a portrait session in harsh light with regular settings (without an ND filter) of f/5.6 and 1/200 sec, with the ND64 / ND 1.8 filter, you could shoot at either f/2.8 and 1/200 sec (to decrease the depth-of-field) or f/5.6 and 1/50 sec (for motion blur).
Sample settings from the AF-S NIKKOR 50mm f/1.8G.

Why Use a Neutral Density Filter?

Using a neutral density filter or graduated filter allows you to master the shot in camera instead of simply relying on post-production techniques to achieve the look you desire. They also give you the creative freedom to capture long-exposure or shallow depth-of-field images during harsh lighting conditions, like in the midday sun.

Are Neutral Density Filters Just For Landscape Photography?

While neutral density and graduated filters are most commonly used by landscape photographers, they are also useful tools for portrait and sports photographers. We cannot always shoot during golden hour, where the light is soft and ethereal, and we can control the depth-of-field in our images much easier. Using an ND filter can help us to achieve a shallow depth-of-field even in harsh light without compromising shutter speed or ISO.

Neutral Density Filters vs Polarizing Filters – What’s the Difference?

Polarizing filters work similarly to polarized sunglasses – they help to reduce glare in harsh light. Polarizers also help to saturate colors when shooting in direct sunlight and they can really bring out the blues in a sky. Polarizing filters do not allow you to adjust your settings to achieve long-exposures, motion-blur or a shallow depth-of-field in the same way that ND filters do.  

Price Points and Quality

As with most photography accessories, there are vast differences in the price point and quality of neutral density filters. Circular ND filters tend to be less expensive than their filter-holder square counterparts, but are often said to be of lesser quality. For those who just want to test out shooting with an ND filter, a circular filter is a good option.  

Downsides to Neutral Density Filters

Like most camera gear, the best quality neutral density filters are expensive. They are an investment item. If using circular neutral density filters, you will need a separate filter for each of your lenses if they have different diameters. If you use the plate-type filter and holder, you may need to purchase adapter rings to ensure they fit onto each of your lenses. There are starter packs that you can purchase, and it is best to talk to your local camera store about what product/brand is right for you.

Neutral density filters and graduated filters will not help you to properly expose the entire scene on a subject that has a protruding object jutting out of the horizon (like a tree or a mountain), so you will need to use another technique (like stacking) in post-production to achieve the desired result.

Finally, ND filters do not block harmful ultraviolet rays. If you wish to shoot the sun (during a solar eclipse for instance), you will need to purchase a special solar filter.  

If you are a landscape, portrait or sports photographer, you will find a lot of use for neutral density filters, and they will make a great addition to your gear bag. Try taking some test shots with and without ND filters to see the difference they make in your photography. Most of all, have fun!