The graduated neutral density filter or GND

In these past few years, buying a DSLR has become so affordable that many people now own one. It has even become a common gift to offer for Christmas or for a birthday. It must be said that the prices have decreased and that for less than 400€, you can buy a cheap DSLR camera, perfect to start and learn photography. As a follow-up to the article on the camera lens filter and its utility, I would like to end my review on filters with the Graduated Neutral Density filter (GND) also known as Graduated ND Filter or ND Grad !

After explaining the advantages, choices and the use of a polarizing filter and a neutral density filter (ND filter), here is a more detailed post on these famous GND filters. I will explain here what they are used for, their benefits and disadvantages, how to choose them, use them and lastly the cleaning and storage of these filters. I also give you my recommendations at the end of the article. So here we go!

For many landscape photographers, it is THE essential filter for great photography. Personally, they never leave my camera bag and I carry them everywhere with me along with my wide-angle lens.

Let’s start with the basics, what exactly is the GND filter? If you are a beginner in photography, you may not be familiar with the concept of a simple neutral density filter (ND). It is kind of the same system, except that instead of being totally opaque (like the ND filter), the GND filter has, as its name suggests, a graduation… Most of the time, these filters are made of resin. Have I lost you? Let me explain.

These filters are therefore opaque, i.e. more or less black, only on a part of the filter. It is generally the upper part of the filter that is blacker, except for the Reverse GND filters, which are especially for sunsets. We’ll talk about it later. Let’s now take a look at the benefits and advantages of using such a filter.

Although digital camera sensors are improving more and more, they are still not performing well enough to detect what a human eye actually sees. In many situations, the scene you are going to take a picture of will have a significant difference in brightness. This could be, for example, a beach in the middle of the day with a harsh light on the sky, usually overexposed. Very often, in landscape photography, you will have a foreground that will be darker than the sky.

The idea is simple, in landscape photography, you will usually focus on the foreground with a small aperture (for example f/11 of f/14). Since it is darker, you will very often overexpose your background (skies will be brighter). This is the main advantage of a graduated neutral density filter.

It will allow, from the moment you take the shot, to reduce the differences in brightness on your picture and to gain in dynamic range on the image. In concrete terms, you will help your DSLR sensor to better expose the scene in front of it. The filter will thus be used to balance the different levels of the picture with its gradient (and you can see this directly from your viewfinder). The amount of light will then be reduced on the sky. If you’re asking, you can of course use a polarizer filter with a graduated filter.

We’ll talk about it at the end of the article, but it can also be used on scenes where the horizon is not “straight”. Mountain landscapes with a mist or atmospheric haze in the background are very good subjects too. Beach or cliff scenes with an offset horizon also work very well. As we will see later, we can use the filter holder to fix the filter on the horizon we want, even if it is tilted.

Finally, the last point which I find very interesting, is that it limits the time you will spend in post-production. If you don’t shoot in RAW and/or edit your photos, it’s certainly not a problem. But for those who spend hours working on post processing, Photoshop or Lightroom, I think you’d be better off in front of your camera in the middle of nature, am I right? Although I am a big fan of computers, I 100% prefer spending time outdoors when it comes to photography.

I am convinced that using a filter of this type is a very good idea, especially in landscape photography. However, it does have some disadvantages:

• The purchase of photo equipment: you’re going to ask me what I’m talking about, I’m buying a filter and that’s good enough, right? Well… actually, no, it’s not that simple. To use a GND filter, you will need a special filter system, composed from two elements: a filter holder that you will place on an adapter ring that will be screwed to your lens. So that’s two accessories to buy in addition to the filter. Count between 100 and 200 € for the 2 accessories depending on the model’s quality,
• The price of filters: if we rely on good quality filters, the price will increase quickly. A filter will cost around 100 to 150€,
• You will most likely need several filters of different types and density (so the bill will add up even more), but we’ll talk about it later,
• GND filters also tend to darken your photo. It will often be necessary to adjust the brightness of you picture,
• Finally, a certain amount of practice will be necessary to be able to use them, even if it is not complicated. It depends on whether you will use them alone or with other filters. I very often use my GND filter with my polarizing filter and my ND filter (for long exposure).

You now have a good idea of the purpose of GND filters but also of the disadvantages. Now let’s see how to make your choice.

In order to choose a GND filter, I would say that there are 3 main criteria: the size, the type of transition, and the density of the filter.

Typically, the graduated neutral density filter is always rectangular in shape. The sizes actually vary depending on the camera lens you are going to place it on. Let me explain. In most cases that will interest you, you will use a GND filter of size 100 x 150.

Some brands also have filters in sizes 70 x 80 or 70 x 100, which are suitable for compact expert and mirrorless cameras. If you’re going to be equipping a DSLR camera, you are not going to need these.

In some special cases, such as wide-angle and ultra-wide-angle lenses from Canon, Nikon, Tokina, Pentax, Sigma and others, you will not be able to use standard size filters. Why? Simply because these lenses have a very wide angle of view and you will see vignetting (black on the edges) appear on your picture. The brands have designed specific filters (and associated filter holders) for this type of filter with a wide focal length. Usually, the size of the filters will be 150x170mm or even bigger, 180x210mm, like these, for example at Lee’s. Of course, with this kind of large filters, the filter holder will also be larger. By the way, if you are looking for more info on this subject, I wrote a full article on special filter holder systems for wide-angle lenses.

The two main brands, Nisi and Lee, each have their own filter holder system and filters. In general, the filters of each brand fit relatively well in the filter holders of the other. This is often specified. This is for example the well-known:

• NiSi V6 Filter Holder 100mm System with NC Landscape Circular Polarizing
• The New Lee filter holder system for 100mm filters

As mentioned above, you will not be able to use a GND filter without an adapter ring for your lens and a filter holder system. This one will thus depend on the size of the filters you need.

The Nisi Filters website explains the different types of filters and filter holders. However, I regret that there is no reference manual to see which photo equipment (filter + filter holder) should be purchased for which lens.

The GND LEE filter site offers an excellent system where all the lenses are listed. By choosing the one you are interested in, it is clearly explained which filter holder system and associated filters you should choose. Very handy in my opinion. This is the classic Lee filter holder, the one I personally own .

If you are in doubt regarding your choice, do not hesitate to contact the brands. Given the price of the whole package, it is better to make the right choice from the start.

Once you have properly chosen the size of your filters and filter holder, it is time to look at the filter graduation systems. As mentioned earlier, the GND filter is opaque, only on one part of the filter, usually on the upper part. It should therefore be understood that part of the GND filter will actually be totally transparent (often at the bottom) and that the higher you go up the filter, the darker the filter will be. Here, we are talking about the transition between the transparent zone and the opaque (black) zone. There are 4 possible types of transitions concerning this type of filter:

• Soft GNDs offer a very soft transition between the opaque and transparent areas. This type of filter is particularly used for situations where a gradual transition is required between your foreground and the sky. It is widely used when there is no clear difference between the light and dark area and that the differences in brightness are a little more subtle. For example: seascapes with mountains in the background, all mountain landscapes, pictures of valley landscapes, in short when the separation between light and dark areas are not obvious.

• GND Hard filters are characterized by a clear and distinct transition between the black opaque area, and the transparent area at the bottom of the filter. In other words, you have a filter that is more or less opaque depending on the density and clearly ends up in the center of the filter. They are particularly well suited for all situations where the transition will be distinct. For example: seascapes and seaside sunsets (even if there is a type of filter specially dedicated to this, the Reverse GND). Be careful when using these filters with hard transitions when there are elements that come out of the horizon, at the risk of seeing them darken completely .

Example of perfect landscapes to use a GND Soft (on the left) and Reverse or Hard (on the right) filters

• Medium GNDs are a good balance between Soft GNDs and Hard GNDs. They offer a slightly harder transition than the soft ones but do not have a clear line like the hard ones. Always to be used preferably on hilly or mountainous landscapes, etc.

• GND Reverse filters are filters specially designed for sunset. They could be assimilated to GND Hard filter, with the exception that the darkest part of the filter is on the horizon. In other words, you have a very black line in the center of the filter that becomes slightly lighter as you progress to the top of the filter. The filters are ideal for sunrise and sunset, as the brightest area in these situations is right on the horizon.

The last criteria to consider when choosing such a filter, and one of the most important, is the density of the filter. Like an ND filter, density refers to the darkness of the filter. The density of GND filters generally refers to “stops”. As a general rule, there is graduation available between 2 and 5 stops.

If you are new to photography, I invite you to read the article on exposure in photography that sums up and explains the different parameters that define the exposure of a picture (ISO, aperture and shutter speed). A stop (otherwise known as “IL”, “EV”) can be considered simply as a variation, a difference, between two values of a picture’s exposure. When you take the same picture at f/4 or f/2.8, you have a one stop difference.

Now, about the GND filter, understand that the higher the “stops”, the greater the difference the photo without filter will have. Simply put, the more stops you have, the blacker your filter will be. Extra attention should therefore be paid to knowing in which particular situation you will use your filters the most. This will depend on your photography style, what you like to take photograph, in what light conditions, etc. If you only take pictures of sunsets, you will be guided directly to a Reverse GND filter.

To complicate the matter, the brands mention the characteristics of the filters according to:

• The optical density of the filter: example 0.6 or 1.2,
• The filter coefficient: the number behind the “GND”: example GND 8 or GND 16. For information, this is exactly the same as for ND filters,
• The filter stops: the difference in light with the same photo without filter.

The following table summarizes this point:

I will explain my recommendations below according to the type of photos you will take in different situations.

A quick point on the adapter rings for the filter holder. You generally have two types of rings: normal and wide-angle special. You can buy them directly with a filter holder (often) or next to it. So be careful to look closely at the diameter of your lens.

As mentioned above, you will first need to equip yourself with all the necessary equipment, i.e. the filter holder system, the adapter ring and your chosen GND filters. If lighting conditions are weak, you will also need a tripod.

To make it simple, here is the general order of use:

1 – Screw the adapter ring onto the lens you are going to use (take off the lens hood most of the time),

2 – Place the filter holder on the adapter ring (make sure that it is properly installed and in place),

3 – Choose the appropriate GND filter for the photo you want to take and place your GND filter in the slot closest to your DSLR camera on your filter holder. If you want to use an ND filter at the same time, the ND filter will usually be placed first, then the GND second,

4 – Looking through the eyelet of your DSLR, correctly place the transition of your filter on the landscape in front of you (you’ll see in live that the filter will be darkening the sky),

5 – Once the filter is correctly set (according to you), take the shot as you usually would (in manual or semi-automatic mode, type Av),

6 – Look at the result on your camera and adjust the horizon line if necessary. The GND filter being slightly to highly opaque depending on the density chosen, will tend to darken the scene and very often, an exposure correction will be necessary, between +1/3 and up to +1 on your camera body.

In practice, you will very often use this type of filter when the light conditions are drastically different between your foreground and your sky, i.e. almost all the time. Living in French Polynesia, in the tropics, the light is very often harsh on the sky and without a GND filter 0.9, or even 1.2, it is very difficult to have a well-exposed picture.

Note also that the filter holder rotates 360° and that it is therefore possible to use a GND filter not only straight, horizontally, but also with an inclination. This is very handy when you have a landscape with a horizon that appears sideways (I’m mainly thinking of seascapes).

You will need to make some tests to make sure that the exposure is correct during the shooting, but using a GND filter in itself is not that complicated.

Considering the cost of the package and especially the filters, I wanted to write a few lines about how to store and clean the filters. Nothing very elaborate here. There are actually two very useful accessories in my opinion:

• A high-quality cloth to clean filters and lenses. Clearly, you’re going to need it, even more so if you’re shooting by the sea, with the water, spray and sand,
• A filter storage system. The two major brands offer them: Nisi and Lee. At Nisi, it is a more robust system than at LEE. It’s good, I think, in terms of protection, but less in terms of space in your camera bag. At Lee’s, it’s a softer pouch. It’s up to you.

In any case, you will need to include in your budget something to store the filters. Be careful to look at the size of your filters in regard to storage. There are of course storage spaces for all sizes, although 100 x 150 is still the most common. You can’t leave them on their own in a camera bag.

Last point of this long post, the choice of your graduated neutral density filters. In the previous paragraphs, I explained everything you need to know about your future acquisition. If I have to summarize, I would say to ask yourself these questions:

1 – Is the purchase intended for a particular lens, such as an ultra-wide-angle Canon 14-24mm on a Full Frame sensor, or Nikon 14-24mm? If the answer is no, proceed to the next step

2 – You will therefore start with a standard size of 100 x 150 for the GND,

3 – Now evaluate in what situation you will use your filter the most: at sea or in the mountains (it is a bit binary), but it is for the choice of the transition. If you live near the sea and you like long exposure, for example, switch to “Hard” directly,

4 – The density will depend on the conditions in which you will take the pictures. I only advise very few GNDs below 3 stops. I am of the opinion that cameras are relatively good at handling small differences of brightness on a scene. So at the very least, I would say a GND8 (3 stops). I have one, and sometimes I still don’t find it opaque enough. I plan to buy a GND16 or GND32 Hard for seaside photography.

Overall, from what I have been able to test and read on the web, two brands stand out: NISI and LEE. However, other brands offer Grads filters such as Rollei, Hitech, Singh ray, Cokin, Haida, Tiffen or even Benro.

To start with, I would say get yourself a GND8 Soft (for everything that is out of the sea), and a GND16 Hard if you take a lot of pictures at the water’s edge. If you can afford a GND Reverse for sunsets, that’s great.

It is obviously impossible to mention all the references I could recommend. In any case, it will often depend on your budget, your photography practice and your camera (FF/APS-C). I suggest here some legitimate referrals for different types of photos and for all budgets.

You can get all GND filters here from Hitech,

I have come to the end of everything I had to say about graduated neutral density filters. You will now be able to choose the right one without any trouble. If you have any questions or things you want clarified, please do not hesitate to leave a comment below the article. If you want to know more about filters, I invite you to discover the polarizing filter.

By the way, I’ve just finished a full test of the KASE K9 filter holder system as well as a set of filters they have (polarizer, ND, GND). Don’t hesitate to have a look at it!

See you soon and have a great picture,

Sylvain