Guide to Neutral Density Filters

Neutral Density Filters Guide: How to Use and Choose the Best ND Filters (with Infographic)

One of the most important elements of any type of photography is creatively capturing and controlling the light without letting it overwhelm your photo.

Master the light and you will be able to use it to achieve the shot you are dreaming of.

Neutral-density (ND) filter can help you reducing the amount of light that enters the camera, allowing for a longer exposure time than would be possible otherwise.

With an ND filter, you can capture an image you wouldn’t be able to by simply using your camera alone, and create an effect that can’t be created using any post-processing software.

In this Neutral Density filters guide, you will learn what ND filters are and why they are an important tool for all landscape photographers. 

Even if you’ve never considered using ND filters on your camera before, this guide will teach you everything you need to know to help you get started.

You will understand why they are growing in popularity with photographers, from passionate to professionals. Let's dive into it.

Infographic 

ND Filters Guide

What is a Neutral-Density Filter?

An easy way to understand what an ND filter does for your camera lens is to compare it to a pair of sunglasses.

It simply provides a filter that allows the light passing through the lens to hit the camera’s sensor in a more uniform way.

You’ll enjoy more accurately captured exposures and colours through the use of this filter.

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While using ND filters won’t specifically impact color, having a more balanced exposure will make the colors in your images much more vibrant and true-to-life.

The word “neutral” implies that this uniformity will occur no matter the lighting or color conditions.

These filters are available in a range of densities to accommodate different conditions and situations.

This will be explained in more detail later, so you can decide which type of filter would be best for you.

When to Use a Neutral-Density Filter

On a bright day, the intensity of the sun can make colors look washed-out and overexposed, even if you’ve accurately adjusted your camera settings.

An ND filter can help darken the scene without losing detail in the shadows, keeping your colors truer without having to do a bunch of post-processing after the fact.

Aperture

You’ll also be able to use a wider aperture.

Since the filter will reduce the light that gets through the lens, you can achieve a beautiful shallow depth of field effect even in bright sunlight conditions.

This would be impossible to capture with a camera without the effect of an ND filter.

Flowing Movement

Using a neutral-density filter to shoot movement can also help provide a more accurate result.

Waterfalls are a perfect example of this.

When you look at a waterfall, you don’t see droplets frozen in time and space; you see actively flowing water, cascading over the rocks.

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Long exposure sunset in Seljalandsfoss waterfalls, Iceland

However, it’s hard to try to capture this flowing movement by using a longer exposure.

You’ll often end up with a completely overexposed image, or at least blown-out highlights from the light hitting the water.

In this case, you can use an ND filter to keep the exposure balanced while leaving your shutter open longer to get the flowing water effect you’re looking for.

This applies to more than just water. You’ll be able to capture beautiful landscapes with softly blurred clouds thanks to the exposure balancing effect of an ND filter.

Leaving the shutter open for a longer period of time allows you to track the movement of the clouds over that period, creating a subtle effect that makes the viewer feel like they are watching the passage of time as the earth turns.

Hiding people

ND filters also have the unique ability to make moving objects appear completely invisible, when combined with a slow shutter speed.

This technique can also be used to achieve a ghosting effect, where you can see the background through the foreground subject in the frame.

Black and White

Finally, ND filters are almost vital for capturing deep shades of grey for monochromatic landscapes.

The varied dynamic range that ND filters provide can bring out the most subtle contrasts to make your black and white images pop.

Neutral-Density Filters vs. Using a Small Aperture

There is a dramatically different result achieved by using a wide aperture and taking a fast shot compared to stopping down a bit and using a longer exposure.

While you can certainly get by with using a small aperture to capture most scenes, all lenses will show a decrease in sharpness with smaller apertures.

When you use an ND filter, you’ll be able to avoid compromising on aperture selection during certain conditions.

This is useful when you’re shooting on bright days, or when your camera’s ISO and shutter speed are limited.

You’ll be able to use a more expensive lens with a wide aperture in a greater variety of situations simply by adding a neutral-density filter.

Basically, an ND filter allows you to shoot with a larger aperture than is necessary to achieve more accurate, interesting, and even hyper-real results.

How to Choose the Right Style of Filter

Generally, lens filters can be found in two styles: screw-on and slot-in.

There are significant variations in price, so it’s good to know what you’re looking for before you begin shopping for the right filter.

Slot-in filters provide more flexibility because they don’t have a specific diameter and can be used with almost any lens.

Screw-on filters offer an air-tight seal to help protect your lens and prevent any dust or scratches, and they can’t be bumped or moved during the shooting process.

The only real disadvantage to a screw-on filter is that you are limited to only lenses that fit the specific diameter size of the filter.

Screw-on filters

These filters are sized by diameter, a number which will correspond to the diameter number found on the top or front of your camera lens.

This is usually expressed in millimeters and, for most digital SLR cameras, will be somewhere between 46 to 82 mm.

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Neutral screw-on ND filter for digital camera lenses.

You can allow a bit of additional flexibility to fit smaller or larger lenses by using step-up or step-down adapters, but these will pose challenges of their own.

A step-up adapter can be awkward to use as it will stick out past the edge of your lens, and a step-down adapter can produce unexpected vignetting, since the filter might block some of the light coming in around the edges of the lens.

There are several brands you can check out when shopping for a screw-on filter, but remember to keep in mind the diameter of the lens you plan to use with the filter most often.

These are some of the best ND filter manufacturers that professional photographers will use.

B+W

This brand is relatively expensive, but offers a very solid build with a low-profile, thin design.

The slimness of this filter can make it somewhat tricky to fit to your lens, but will get easier with practice.

The B+W ND filters boast dirt, water, and scratch resistant coatings, which is especially nice when you’re shooting landscapes in a variety of weather conditions.

However, reviews indicate that some users have noticed a slightly noticeable red tint, so someone looking for more accurate color may want to consider a different manufacturer.

Hoya

Hoya Filters are one of the most well-known brands, a household name with photographers worldwide.

The “Metallic ACCU-ND” coating that Hoya uses claims to provide the most accurately rendered color, providing reliable color balance even across all filter strengths.

This brand isn’t quite as slim as some of the others, but still doesn’t result in any unexpected vignetting.

It’s also quite expensive, but offers exceptional results and is likely well worth the investment for a travel or landscape photographer who needs a reliable ND filter.

Slot-in filters

This style of filter will be mounted to the outside of your lens, meaning you can use them with almost any lens size.

Most mounts come with several slots, so you can layer different filters to achieve a wide variety of effects, even allowing you to combine ND filters to expand your range of densities.

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closeup ND filters, Photography equipment

These are somewhat cumbersome, however, and take some time to fasten to the camera.

They also don’t protect your lens like screw-on filters do, and you can actually risk scratching the lens when switching between filters.

After you’ve purchased the mount, slot-in filters are usually less expensive than screw-on filters, and if you like to switch lenses often, this might be a more economical choice.

There are several great manufacturers to choose from when looking for the right slot-in filter, and you’ll have a bit more flexibility shopping for these because you won’t be limited to filters that fit the diameter of your lens.

Lee

A favorite of professional photographers, Lee Filters are engineered to an extremely high standard.

This filter features foam padding around the edges to help prevent stray light from entering the frame, and provides excellent and reliable light reduction for long exposures even in very bright light.

Formatt-Hitech

This manufacturer boasts robust construction with the “highest quality broadcast glass,” but is a bit awkward to handle.

Formatt-Hitech Filters are also less expensive than many other brands, which is helpful for when you’re just starting out with ND filters and require the mount, as well.

The resulting image quality is excellent, according to reviews, and the Formatt-Hitech filters provide very accurate color rendering.

All in all, this is a good value filter for beginners and professionals alike.

How to Choose the Right Density

Neutral-density filters are sold in varying levels of density, approximately equal to f-stops.

You’ll need to choose the appropriate density to suit the shooting conditions you’ll be facing, as each density will produce slightly different results.

As the number of stops gets higher, the filters will become more and more opaque, limiting the amount of light that passes through.

Read on to find out when you should use each type and what you can expect to see in your final images.

3-stop Neutral Density

For photographers who primarily shoot portraits, weddings, or video, this filter is a vital element to keep in your camera bag.

A 3-stop filter will allow you to use the lowest f-number for a shallow depth of field, perfect for isolating your subject and taking a clean portrait.

This filter also lets you use the lowest possible ISO, ensuring smooth, sharp images with accurate, saturated color.

6-stop Neutral Density

This is an ideal filter for landscape photographers. If you’re looking to shoot long exposure sunsets and sunrises, gently moving clouds, and flowing waterfalls, a 6-stop ND filter will give you a perfect balance of versatility and performance.

While most professional landscape photographers will generally have a range of ND filters, this would be the “desert island” choice, if there could only be one.

For a two- to four-minute exposure with a 6-stop filter, you’ll be able to shoot in stunning blue hour and golden hour light conditions with an ISO of 100 and an aperture setting between f/11 and f/18.

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Lake Liptovska Mara, Slovakia. Long exposure shot with ND filter

10-stop Neutral Density

If you’re looking for dramatic results, this is the filter for you. A 10-stop ND filter, like the Lee Filters Big Stopper, allows you to push exposure times during the brightest parts of the day, ideally between 10 a.m. to 4 p.m., when the light is flat, harsh, and directly overhead.

With this filter, you’ll be able to open up your shutter and let cars and people become invisible, and pull out richer grey tones for monochromatic images.

A 10-stop filter is not recommended for shooting sunsets or sunrises, though. It is too dark for low-light photography.

Instead, this filter is better suited to shooting urban environments, abstract black and whites, or landscapes in stark, bright environments.

It’s also possible to achieve a similar effect to using a 10-stop ND filter by stacking the 3-stop and the 6-stop.

This gives you a bit more versatility for shooting during these harsh lighting conditions without investing in a 10-stop filter, especially if you primarily shoot in lower-light conditions.

12-stop Neutral Density 

Even in the middle of the day, a 10-stop filter might not be enough for an exposure of longer than 30 seconds to one minute.

If you want to shoot two to four minute exposures in direct light, you will likely need to step down even further.

A 12-stop ND filter will give you even more dramatic results and provide further flexibility for bright-light shooting.

Again, you could resolve this problem by stacking the 10-stop and 3-stop filters.

However, if you live somewhere bright like Alaska or Florida and are regularly dealing with harsh light, a darker filter may be worth the investment.

If you’re not sure how to expose for certain conditions with specific filters, you can always use an ND Filter Calculator. You can get free apps on your Android or iPhone now.

How to Use a Neutral-Density Filter

If you’ve never used an ND filter before, don’t worry, they’re a very easy addition to any camera setup.

These tips will guide you through the process step-by-step so that you can understand everything you need to know about how to use your new ND filter and start taking better photos.

1. Stabilize your camera

Since you’ll be using a slower shutter speed, it’s important that your camera is secured before you take your shot.

Use a sturdy tripod if you have one, and if you don’t, make sure whatever you’re resting your camera on won’t be moved during the exposure.

However, if you’re serious about pursuing landscape photography as a hobby or a career, you should consider investing in a good tripod for shoots like this.

2. Set up your camera without the filter

Using a neutral-density filter can make your viewfinder seem very dark, making it somewhat challenging to compose an image.

Many photographers work around this by setting up the capture ahead of time, placing the filter over the lens just before triggering the shutter.

You should set your camera to manual and focus the lens on your subject. Autofocus will struggle to find something to focus on after the filter is applied, so make sure your autofocus is switched off after you have your image composed.

You’ll also want to ensure that your ISO is set as low as possible to keep noise down, especially for longer exposures.

3. Put the filter on and determine the shutter speed

Depending on the density of the filter and the number of stops the filter cuts out, you’ll need to adjust the settings on your camera.

You can count the stops manually and then use an ND calculator app to determine the right shutter speed.

Of course, there’s nothing wrong with trying to figure it out on your own and experimenting until you get the results you want.

For beginners, though, it can be helpful to use an app to get an idea of where to start, and adjust from there.

4. Use a remote trigger to release the shutter

As a general rule, if you’re using a shutter speed greater than a couple of seconds, it’s always best to stabilize your camera and use a trigger to release the shutter.

This helps prevent any movement or camera shake caused by your finger pressing down on the button, so you’ll get a much sharper, crisper result.

Before You Go

Now that you know how to choose the right ND filter to suit your primary locations and type of photography, you’ll be able to incorporate this new tool into your process.

You’ll be able to take a well-composed landscape shot from beautiful to spectacular by following the easy steps outlined in this guide.

With a camera bag stocked with ND filters of varying densities, you’ll be well-prepared to deal with all kinds of lighting situations and environmental challenges.

You’ll have the freedom to make interesting creative decisions in the field, instead of relying on post-processing to achieve the dramatic effects you’re looking for.

It’s easy to see why more and more hobbyists and professionals are starting to use ND filters to shoot more dynamic images. And now, you have the knowledge to stay on top of the game right along with them.

Before too long, you’ll have tips of your own for making the most of this important tool, so feel free to leave feedback with your suggestions, or even just a comment letting us know what you thought of this guide.

Guide to Neutral Density Filters

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About the Author Luca

Hi, I am Luca, founder and editor in chief at photographyambition.com. I am crazy about photography and I always have a camera with me. When I am not busy with my day job, enjoying my family or taking photos, I am on Photography Ambition to share what I have learnt so far.

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