Your Breakdown of Lens Filters

Published June 13, 2024

We’ve talked about filters on the blog a few different times before – from Roger’s deep testing of the clarity levels of UV filters to my discussion on how to use ND filters to help balance natural and artificial lighting on location. But despite these years of articles about various filters, I noticed that we’ve never had a basic breakdown of what each filter does, and why you might use them. So let us dive into the topic.

Types of Filters

There are a couple of different configurations of filters, so I thought that before we start breaking down what each type of filter does, and its use case, we should first talk about the few different formats of filters.

Circular Filters

The most common form factor of filters is a circular filter, which is designed to sit in front of the front element of a lens. This means these types of filters usually come in a variety of sizes (usually marked in millimeter sizing), as different lenses have different-sized front elements. These filters also come in two forms – static and adjustable. Static filters are just that, they’re static, and do not rotate when screwed onto the front of the lens. Adjustable filters will often allow you to rotate the filter to make adjustments to the effect. We’ll go into what these adjustments do when we dive into the different types of filters.

Square filters

K&F Concept Filter system

Square filters are a more universal approach to filters and will require a filter holder to best operate. The idea of square filters is that you can use it on a broad range of lenses and camera systems, even if you don’t have a filter screw on the front of your lens. These filters are a plane of glass, usually 100mm x 100mm in size, that mount to a filter holder that attaches to your camera or lens.

Drop in Filters

Drop-in filters are similar to circular filters but are designed to be dropped into the lens, through the use of a filter holder. These are typically found in high-end telephoto lenses, which often have front elements too large for more conventional circular filters. These filters, usually small circular filters mount to a holder built into the lens, and usually place the filter closest to the camera sensor, as opposed to the end of the lens.

Now that we have an idea of different form factors, let’s touch on the four different categories of lens filters.

UV Filters

The first filter on the list is the UV filter. Designed as a filter to help block UV light from damaging your film, it has far less purpose in the digital era and is now largely used to protect your front element. Of all the filters on this list, we’ve tested these the most, as while we have found they can reduce sharpness in images (particularly the cheaper filters), they are still worthwhile for their ability to protect the camera lens. Replacing a front element can cost anywhere from $250-$1500 depending on the lens, so it might be worthwhile to use a UV filter – particularly if you’re clumsy.

Polarizing Filters

Polarizing filters are an essential tool to have in your camera bag – particularly if you photograph reflective surfaces. What a polarizing filter does, is block light from entering the camera lens depending on the angle of light, allowing you to adjust and remove reflections from surfaces by rotating the filter on your lens. Using a polarizing filter is easy (particularly if you’re using natural or constant light), you simply frame your shot and then spin the filter until you see the reflections disappear. If you want a deeper dive into the science of polarizing filters, 20/20 Mag has a great explanation of how they work.

Left- No Polarizer | Right – Polarizer to Reduce Reflections

Neutral Density Filters

Neutral Density filters are designed to restrict the amount of light entering your camera – and I’ve always described them as the ‘Sunglasses for your camera’. So why would you want to restrict the amount of light entering your camera? Well, if you’re using flashes, you may want an ND filter to help restrict your shutter speed to better blend your flash with natural light. Or if you’re shooting in a very bright environment, you may need to use an ND filter to help limit your f-stop. I’ve talked about ND filters and how to use them in the past, but they’re an essential tool in every camera bag.

Specialty Filters

There is no limit to the number of specialty filters available, so it would be impossible to cover them all, but we can touch on a few of the most popular options. If you want even more options, Prism Lens FX has a large collection of different specialty lens filters to check out. But let’s dive into the more popular specialty lens filters.

Black Pro Mist

Black mist filters have become increasingly popular in recent years, and are a great way to add a cinematic effect to your images. The filter will actually decrease contrast, and by proxy, sharpness in your images, but the effect will give a natural hazy look to the images that when done right, looks like film. This filter works by embedding black particles into the filter, which help scatter the light and give a soft glow to the highlights.

Image by Tiffen Filters.

Star Effects

Star filters have a grid-like pattern etched into them, and will help reflections appear as stars. They usually come in a few different variations, from 4-point stars, up to 10-point stars. This grid pattern on the filter will help catch the beams of light in reflections and further flare them out, giving the star quality. However, like most filters, using these will also sacrifice the sharpness of your images.

Prisms & Other Effects

A common specialty filter is one that takes the design of prisms and puts them into a filter form factor for easier use. As mentioned before, a common brand that does this is Prism Lens FX, and these filters are meant to refract light in interesting ways to create reflections, flares, and other obstructions in the images.

And that’s an overview of the different filters to use in photography and their purpose. When buying filters, it’s recommended to buy one at the size of your largest lens (or I usually buy 88mm), and use step-up rings to ensure it fits all of your lenses properly. What are some of your favorite filters? Do you have some examples of them in use? Feel free to chime in in the comments below.

Author: Zach Sutton

I’m Zach and I’m the editor and a frequent writer here at I’m also a commercial beauty photographer in Los Angeles, CA, and offer educational workshops on photography and lighting all over North America.
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