Photography Lens Filters Explained
Lens filters are an essential accessory for any photographer, allowing you to alter the way your camera captures light and get creative with your images. Whether you're looking to reduce glare, enhance colours, or protect your lens from damage, there's a filter that can help you achieve your desired effect. In this article, we'll explain the different types of lens filters available, how they work, and when to use them to get the best results. Whether you're a beginner or an experienced photographer, learning about camera filters is a valuable skill that can help you take your photography to the next level.
What is a camera lens filter?
Lens filters are transparent or semi-transparent attachments for the front of your camera lens to alter the way your camera captures light.
Within this article, we will look at and explain the following camera lens filters:
Circular polarizer/linear (CPL) filters;
Neutral density (ND) filters;
Graduated neutral density (GND) filters;
Pro-Mist filters;
UV filters;
Warm, cool and colour filters; and
Close-up filters.
In addition to the types of filters, this article will also look at:
Lens filter materials; and
How to pick the right size filter for your lens.
Circular polarizer/linear (CPL) filters
CPL filters, also known as circular polarizing filters, are filters that are used in photography to reduce reflections and glare in an image. They work by blocking out certain wavelengths of light that are reflected off of non-metallic surfaces, such as water, glass, and other reflective materials. CPL filters are particularly useful for outdoor photography, as they can help to reduce the amount of glare and reflections that can be caused by the sun or other bright light sources.
At the minimum effect, the filter will allow the most light to pass through and will have the least amount of polarization. At the maximum effect, the filter will block the most light and will have the greatest amount of polarization. The degree of polarization can be adjusted to suit the specific needs of the photograph, and it can be used to create a range of effects, from subtle to dramatic.
CPL filters can also be used to enhance the colours and contrast in an image, as they can help to saturate the colours and increase the separation between different tones. These filters are typically used with DSLR (digital single-lens reflex) cameras and other cameras that have interchangeable lenses, such as mirrorless cameras.
CPL filters are called "circular" because they have a special coating that helps to reduce reflections and improve image quality. They can be adjusted by rotating the filter in front of the lens to vary the amount of polarization, and they are a useful tool for a variety of photography applications, including landscape, portrait, and nature photography.
Neutral density (ND) filters
In photography, an ND (neutral density) filter is a filter that reduces the amount of light that enters the camera lens. It can be used to reduce the overall exposure of a photograph, or to enable the use of longer exposure times in bright light to create a blur effect. ND filters come in different strengths, measured in stops of light. For example, an ND2 filter reduces the amount of light by 1 stop, an ND4 filter reduces it by 2 stops, and so on. They can be useful for a variety of creative effects, such as creating a sense of motion in a photograph by using a long exposure time to blur moving objects, or for reducing the depth of field in a photograph by using a wide aperture in bright light.
Graduated neutral density (GND) filters
GND filters are filters that are used in photography to darken specific areas of an image. They are typically rectangular in shape and are made of a transparent material that is darker at one end and gradually becomes lighter towards the other end. GND filters are used to balance the exposure between the bright and dark areas of an image, such as when shooting a landscape with a bright sky and a darker foreground. By placing the darker end of the filter over the bright sky and the lighter end over the darker foreground, the photographer can reduce the overall exposure of the image and create a more balanced, natural-looking photograph. GND filters are available in various strengths and gradations, and they can be used with both film and digital cameras.
What is a hard-edge graduated neutral density (GND) filter?
A hard-edge graduated neutral density (GND) filter is a type of GND filter that has a distinct, hard transition between the darker and lighter areas of the filter. This means that the line between the dark and light areas of the image will be very clearly defined, rather than being gradually blended together. Hard-edge GND filters are most commonly used when there is a clear, defined line between the bright and dark areas of the scene, such as when shooting a landscape with a horizon line. They are often preferred in these situations because they allow the photographer to more accurately control the transition between the bright and dark areas of the image. However, they may not be as effective in situations where there is not a clear, defined line between the bright and dark areas, as the transition may appear too abrupt or unrealistic.
What is a soft-edge graduated neutral density (GND) filter?
A soft-edge graduated neutral density (GND) filter is a type of GND filter that has a gradual, soft transition between the darker and lighter areas of the filter. This means that the line between the dark and light areas of the image will be more blended and subtle, rather than being clearly defined. Soft-edge GND filters are most commonly used when there is not a clear, defined line between the bright and dark areas of the scene, such as when shooting a landscape with a hazy horizon or with trees or other objects in the foreground. They are often preferred in these situations because they allow the photographer to create a more natural-looking transition between the bright and dark areas of the image. However, they may not be as effective in situations where there is a clear, defined line between the bright and dark areas, as the transition may appear too subtle or may not cover the entire area that needs to be darkened.
What is a reverse graduated neutral density (GND) filter?
A reverse graduated neutral density (GND) filter is a type of GND filter that is darker at the top and gradually becomes lighter towards the bottom. It is the opposite of a traditional GND filter, which is lighter at the top and darker towards the bottom. Reverse GND filters are used to darken the top portion of an image while leaving the bottom portion unchanged. They are most commonly used in situations where the bright area of the scene is at the bottom of the frame, such as when shooting a sunrise or sunset where the sun is low on the horizon. Reverse GND filters can be used to balance the exposure between the bright and dark areas of the image and to create a more natural-looking photograph.
Pro-Mist filters
Pro-Mist filters are a type of special effects filter that is used in photography and videography to soften and diffuse the appearance of highlights and shadows. They are designed to reduce contrast in an image and create a hazy, ethereal look. Pro-Mist filters are available in various strengths, ranging from light to heavy, and can be used to achieve a variety of effects, from subtle to dramatic. They are often used to create a softer, more cinematic look in films and television shows, or to give a dreamy, romantic look to portraits. Pro-Mist filters work by diffusing the light that passes through them, which helps to soften hard edges and reduce the appearance of blemishes or other imperfections in the image.
UV filters
UV filters are filters that are used in photography to block out ultraviolet (UV) light. UV light is a type of electromagnetic radiation that is not visible to the human eye, but it can have a noticeable effect on photographs, particularly those taken at high altitudes or in other situations where the air is thin and the UV light is more intense. UV filters work by blocking the UV light before it reaches the camera lens, which helps to reduce the amount of haze that can be caused by UV light in photographs. UV filters can also provide some additional protection for the camera lens, as they can help to reduce the amount of dust, dirt, and other debris that can accumulate on the lens over time.
Warm, cool and colour filters
Colour filters, also known as warming or cooling filters, are filters that are used in photography and videography to adjust the colour balance of an image. They are available in a range of colours, including red, orange, yellow, green, blue, and purple, and each colour has a different effect on the image.
Warming filters are filters that are used to add a warm, orange or yellow cast to an image. They are often used to counteract the cool, blue tones that can be present in images shot in shade or on overcast days, or to create a warm, cozy atmosphere in portraits or other types of photographs.
Cooling filters are filters that are used to add a cool, blue cast to an image. They are often used to counteract the warm, orange or yellow tones that can be present in images shot in direct sunlight, or to create a cool, refreshing atmosphere in photographs.
Colour filters can be used with both film and digital cameras, and they can be particularly useful for fine-tuning the colour balance of an image in post-processing. However, they can also be used in-camera to create a desired colour effect in real-time.
Close-up filters
A close-up filter, also known as a macro filter or a close-up lens, is a type of filter that is used in photography to allow the camera to focus on objects that are close to the lens. Close-up filters are typically used with telephoto lenses or standard lenses to enable them to focus on subjects at close range, such as flowers, insects, and other small objects. They work by magnifying the image and reducing the minimum focus distance of the lens, which allows the camera to focus on objects that are closer to the lens than it would normally be able to do. Close-up filters are available in different magnifications, ranging from +1 to +4, with higher numbers indicating a stronger magnification. They can be a useful tool for photographers who want to capture close-up shots of small objects or for those who want to experiment with different focus effects.
Lens filter materials
Lens filters are typically made of glass or a transparent plastic material such as acrylic or polycarbonate. The type of material used will depend on the specific properties of the filter and the intended use. Glass filters are generally more durable and scratch-resistant than plastic filters, but they are also heavier and more expensive. Plastic filters are lighter and less expensive than glass filters, but they may be more prone to scratching and may not have the same optical quality as glass filters. Some high-end lens filters are made of special types of glass or other materials that are designed to provide optimal image quality and durability. Regardless of the material used, the most important factor in the quality of a lens filter is the coatings that are applied to it. Multi-coated filters are typically of higher quality than uncoated or single-coated filters, as they can help to reduce reflections and improve image clarity.
How to pick the right size filter for your lens?
The size of the filter you need depends on the size of your lens. The size of your lens is indicated by the diameter of the front element in millimetres. You can find the size of your lens printed on the front of the lens or in the specification sheet that came with the lens.
Once you know the size of your lens, you can purchase a filter that is the same size or slightly larger. It is important to make sure that the filter you choose is not too small, as it will not be able to cover the entire front element of the lens and may cause vignetting (dark corners in your photos).
It is also a good idea to check the thread size of your lens, as some lenses may have non-standard thread sizes. You will need to make sure that the filter you choose has the correct thread size to fit your lens.
Photography lens filters explained - Conclusion
In conclusion, lens filters are an important tool for photographers and videographers, as they can help to enhance the quality and creativity of their images. There are many different types of lens filters available, each with its own specific purpose and effects. ND filters can be used to reduce the overall exposure of a photograph or to enable the use of long exposure times in bright light. Pro-Mist filters are used to soften and diffuse the appearance of highlights and shadows, while UV filters block out ultraviolet light to reduce haze in images. CPL filters reduce reflections and glare, and GND filters are used to darken specific areas of an image. Colour filters, also known as warming or cooling filters, can be used to adjust the colour balance of an image, and close-up filters allow the camera to focus on objects that are close to the lens. By understanding the different types of lens filters and how they can be used, photographers and videographers can expand their creative possibilities and produce better-quality images.