Filters can help photographers in several different scenarios and two of the most common filters are neutral density filters and graduated neutral density filters. Both are very commonly used in landscape photography, but they are used for different reasons and in different situations. This article will cover the details of both, how they work, and when they should be used.
Table of Contents
Neutral Density Filter
Neutral density (ND) filters are used to reduce the amount of light passing through the lens. The filter is made of dark glass and is fixed in front of the lens so that some of the light is blocked from entering. Because less light is able to reach the camera’s sensor, a slower or longer shutter speed must be used in order to get a properly exposed photo. When you want to capture a long-exposure photo, using a neutral density filter may be necessary in order to get a properly exposed image.
Landscape photographers might use a neutral density filter in order to capture a photo that blurs moving water (like a waterfall or cascading creek). You’ve probably seen photos of waterfalls that look silky smooth. This is accomplished by slowing down the shutter speed, which blurs the water due to the movement.
Another common use for ND filters is to showcase movement in the sky. If the clouds are moving quickly, a long exposure photograph can capture that movement by showing blurred clouds. This can be especially effective during a storm or when the sky looks dark and dramatic.
Graduated Neutral Density Filter
A graduated ND filter is used to lessen the amount of light entering and reaching the camera sensor, but only for part of the photo. The “graduated” part of the name refers to how the glass of the filter transitions for dark glass that blocks light to clear glass that allows the light to pass through. Graduated neutral density filters are used to create balanced exposures when the light is drastically different at various parts of the scene.
Again, these filters are commonly used in landscape photography. Imagine you are photographing a canyon from above. At the rim of the canyon the sun is shining and the light is bright. But the lower parts of the canyon are deep in shadow. You could use a graduated neutral density filter to block some of the light above the horizon without blocking any light in the darker areas of the canyon.
Graduated neutral density filters need to be adjusted so the dark side of the glass is lined up to block the brightest light. Some of these filters are circular and screw on to the front of your lens. You can then turn the filter to get it lined up properly. Some of the filters are rectangular and fit into a filter holder that screws on to the front of the lens. In this case, you would adjust the holder to get the filter lined up properly.
The Differences
Neutral density filters and Graduated neutral density filters have significant differences in terms of their functions, usage, types, and appearance.
The major difference between these two is that ND filter darkens the entire image and stop some of the light for the entire image whereas graduated ND filter only darkens a certain part of the image.
The round filters are designed for specific sizes ranging from 40.5mm to 95mm. When you’re purchasing a circular filter, you need to make sure that you are purchasing the right size for your lens. If you plan to use the filter with multiple lenses, you may need to buy multiple filers if your lenses are different sizes.
There are many level variations of these filters because sometimes you need to block more light than others. The darker the glass, the more light it will block. The more light that’s blocked, the slower shutter speed you will need.
Square ND filters also possess the same qualities but they are attached with the help of filter holders because of their shape. They are not directly screwed onto the lens. These filters can be rotated in order to align in it correctly.
Another way that these filters can differ is in terms of the transition. While neutral density filters are solid, graduated neutral density filters will transition from dark glass to clear glass. That transition can be soft (gradual) or hard (sudden). A softer transition will allow the photo to have a more balanced look without any obvious change in the exposure. A hard transition can be used in a case where there is a straight line that is significantly blocking the light. For example you might use a filter with a hard transition and line the transition up with the edge of a building that is blocking part of the light. In most cases, you’ll probably use a filter with a soft transition.
Functions
The function of these two filters are different too, and that’s why they are used for different purposes. Neutral density filters are used to have longer shutter speed so that movements can be blurred, which can give a pleasing effect to the picture. This gives a dreamy effect if moving water is captured through this filter. ND filters are used to darken sunlight in images. Hence, when an ND filter is adjusted to the camera, it can help you keep the aperture wide open, lower your shutter speed to get the correct exposure, and get a creamy effect in the overall picture.
Graduated ND filters are used for balancing the image by darkening certain parts of the image and highlighting the subject that needs to be focused. These filters also keeps the original details and sharpness visible in the image and controls the light exposure reaching the camera sensors. These filters define landscapes and give a finished look.
Moving towards the usage of the filters, their application is completely different too. Shooting outside can be challenging in certain lighting conditions. These filters are the best choice when a photographer is worried about overexposed skies in a landscape. Graduated ND filters darken overexposed skies and keep the other part of the picture bright and light because of its half transparent and half dark feature. Whereas, waterfalls, moving trains, traffic, and other kinds of
movements in a picture are captured better by neutral density filters. This is done by slowing the shutter speed and taking long shots in order to define depth and give a dreamy effect.
ND filters are available in various filter densities and it ranges from 1-stop to 15-stop and it depends completely on the usage of the photographer. According to the concept of the image, a suitable density is selected.
Graduated neutral density filters come in densities ranging from 1-stop to 4-stop. The most commonly used varieties are 2-stop and 3-stop.
As mentioned above, both of these filters serve their purpose accordingly and they have their own functions, applications, and types. They both are entirely distinct and different when it comes to their characteristics. These filters lessen the post-processing work and burden on the editor. Neutral density and graduated neutral density filters are recommended to be used when and where needed and they should be a part of your camera gear if you photograph landscapes.