Camera Lens Filters Explained [Beginner’s Guide]

Rajib Mukherjee Avatar
Rajib Mukherjee
18 January, 2023 • Updated 1 year ago
lens filters explained
A lens filter is an apparatus that sits or screws onto your camera lens to capture image qualities your camera is not otherwise able to produce. There are a plethora of lens filters available that help achieve different goals, such as managing exposure or eliminating glare.

In this article, I will cover the different types of filters, what they do, as well as how to use them.

Haze/UV filters /Clear and Skylight Filters

panorama of the city, through a lens filter

UV or haze filters are filters used to cut through the atmospheric haze. Apart from the atmospheric haze, they help to overcome the issues of moisture, dirt, and suspended particles that create reflections that bring down contrast in your images. They also help to cut down on UV light. However, it must be mentioned that UV light isn’t a major issue with digital sensors. This light affects film more than digital sensors, and therefore they were widely used by landscape photographers who shot with film.

If you’re looking to pop the saturation and color of your images, try these filters for better results. These filters come in different strengths. Therefore, depending on the shooting situation, you may need a stronger UV filter or a milder one.

Some lower-strength UV filters are also used for protective filters. Protective filters, as the name suggests, protect the lens’s front element from knocks, bumps, and scratches. If you use a UV filter simply for protective purposes, ensure it has a lower strength.

A better option would be to use a clear filter. However, some clear filters, especially the cheaper ones, are known to induce color cast. So always buy good quality clear filters because these serve as a second set of glass in front of the lens and can potentially affect the quality of the images.

Skylight filters are primarily used to counter the excessive blue cast when shooting under a clear, blurred sky. They’re also helpful in removing color reflections that can affect skin tones. It’s not a good idea to use a skylight filter as a protective filter if that is your main intention. 

Polarizing Filters

DSLR camera with Polarizing filter

It is often said that a polarizing filter is a landscape photographer’s best friend. You should never leave home without it if you plan to shoot landscape photography.

The purpose of polarizing filters is to cut down on glares and reflections and, in the process, increase the saturation of your images. These are screw-on type filters that screw onto the front of a lens. Once the filter is placed on the front of the lens, you can gently rotate the front free-rotating section to adjust the effect of the filter.

Polarizing filters are best used to manipulate the contrast of skies and counter reflections. Thus, they’re ideal for capturing photos of landscapes, waterfalls, streams, views through windows, etc. They can shoot through the glare of reflective surfaces like window panes and show windows. If you love capturing photos of streams, polarizing filters can also minimize the glare produced by the water.

Polarizing filters have a bit of a learning curve. If you have seen pictures where the sky or a portion of the sky seems unrealistically blue, the photographer has likely overcompensated with the polarizing filter. Getting this right can sometimes take some trial and error.

There is something called a maximum and a minimum effect of polarization. The maximum polarization is achieved for the best effect when the lens is pointed in the direction of 90 degrees from the sun’s position. You can quickly figure out where the maximum effect would be with this simple exercise. Make a pistol figure using your thumb and your index finger. Point your index finger towards the sun and rotate your thumb clockwise and anticlockwise. The maximum polarization effect will be achieved where your thumb points at any given time.

ND Filters

ND Filter in the hand

In a previous discussion, I briefly mentioned ND filters. In this article, I will explain more elaborately the different uses and benefits of ND filters.

If you look at an ND filter, they’re nothing more than dark-colored glass, similar to the sunglasses we wear on a bright, sunny day. The purpose of ND filters is to block particular light from entering the camera to manage exposure, negate the need for a lens or provide a particular image style.

Since ND filters stop light when you’re using them and shooting with a slower shutter speed, you have to ensure that your camera is set up on a tripod. This will ensure that when a slow shutter speed image is being exposed, the camera does not move and therefore does not become blurry.

The strength of an ND filter is always mentioned in stops of light. An ND 2 stops one stop of light, an ND 4 stops two stops of light, an ND 8 stops three stops of light, and so on. Different ND filter manufacturers have different ways to express the strength of their ND filters. So a one-stop ND filter can also be expressed as 0.3 ND. A two-stop ND filter can be expressed as 0.6 ND and so on.

Check the lens packaging to identify how a particular ND manufacturer marks its filters. The details are provided both on the package and the side walls of the filter.

How does a particular ND filter affect exposure? Let’s say that the usual direction is 1/250 sec. With an ND 2 or a 0.3 ND, the new shutter speed will be 1/125 sec. With an ND 4 or a 0.6 ND, the resulting shutter speed will be 1/60 sec. Similarly, with an ND 8 or a 0.9 ND, the resulting shutter speed would be 1/30 sec. With an ND 10 or a 3.0 ND, the correct shutter speed will be 4 seconds.

ND filters can be variable and graduated. Let’s look at both of them here.

Variable ND Filters

the camera on a stump in winter

Variable ND filters are rotatable. When you rotate them like circular polarisers, their light-stopping power tends to increase or decrease depending on the direction in which you’re rotating them. So one filter aims to do the job of multiple ND filters.

A good quality variable ND filter is a great tool to have for someone who is a landscape, cityscape, or outdoor photographer in general. Just like you shouldn’t leave home without a circular polarizer, if you have a variable ND filter that matches the filter thread of your best landscape lenses, you shouldn’t leave home without it.

Graduated ND Filters

highway in the desert against the blue sky and mountains

As the name suggests, graduated ND filters or grad ND filters have a clear side and a light-stopping side. These filters are ideally suitable for landscape photography, especially where one part of the frame (usually the sky) is very bright and the other (i.e., the ground) is relatively dark. You can set these filters up to match the transition line along the horizon and shoot excellently balanced exposures. This saves a considerable amount of time due to not having to adjust the exposure in post-processing.

Just like ordinary ND filters have different strengths of light-stopping power, grad ND filters do too. This allows you to choose the right grad ND for the scene you’re trying to shoot.

Also, grad NDs come in different types, namely hard-edged grand NDs, Soft-edged grad NDs, and reverse grad NDs. Hard-edged grad NDs have a very harsh transition line, which is ideal for a hard transition between the frame’s bright and dark sides.

As the name suggests, soft-edged grad NDs have a relatively soft transition line. These are ideally suitable when the scene’s transition between the dark and the brighter areas is not that clearly defined.

Finally, the reverse grad NDs are tailor-made to shoot fantastic sunsets. This is because, as the name suggests, the light-stopping side has the light-stopping coating in reverse. Instead of a darker top side and a lighter middle area followed by a clear bottom part, the top part is the darkest transitioning to a lighter middle part and a clear bottom part.

Graduated filter tools can help you overcome a difficult lighting situation without needing complicated editing in Lightroom and Photoshop. These filters can take sunsets, sunrise shots, golden hour shots, and many more.

Color Correcting Filters

sandy beach against the blue sky

Color-correcting filters are also known as warming filters and cooling filters. The primary purpose of these filters is to correct the white balance of your images. They can also enhance the color of your scene, depending on the effect you are trying to achieve.

Many people make use of editing to color correct, but finding the right filter can cut down on the time it takes to produce your signature photography style.

Apart from color correction filters, there is another type of filter known as color subtraction. The job of these filters is to absorb one particular color and allow all other colors to pass through.

These days, thanks to the advent of digital cameras and the subsequent switch to shooting in RAW, photographers can bypass this process and choose white balance adjustment during post-processing. This has made these filters somewhat redundant.

Close-up Filters

lens filter zoom scale

The advantage of using close-up filters is that they allow you to use your standard regular lens for shooting macro photography.

These filters screw on the front of a lens and impart close focusing properties. This negates the need to buy dedicated macro lenses for shooting macro photography. Dedicated macro lenses can be costly and this is an inexpensive and effective alternative.

However, there is a flip side. Dedicated macro lenses are designed to offer a 1:1 magnified view that close-up filters cannot provide. Therefore, these filters are no match for the power and versatility macro lenses provide.

Rajib Mukherjee Avatar
Rajib is an avid travel photographer and an overall shutterbug. The first time he ever clicked an image was with an Agfa Click IV back in 1984. A medium format film camera. From that auspicious introduction to photography, he has remained hooked to this art form. He loves to test and review new photography gear. Rajib travels quite a lot, loves driving on Indian roads, playing fetch with his Labrador retriever, and loves photography. And yes, he still proudly owns that Agfa Click IV!
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