Race cars are great, but they sure do have a lot of reflective surfaces. That’s why using a polariser is essential when you are photographing motorsport.

I’ll give you a hot tip: I’ve got enough polarisers (polarizers for the Americans reading this) in my kit to ensure that there is one attached to every camera I’m using if I need to. That’s how important they are to motorsport photography.

Using a polariser filter reduces glare and reflections on not only the surfaces of race cars but also the racetrack as well. Resulting in clearer and more vibrant photos no matter what the sun is doing. They also open up opportunities to photograph the on-track action from more angles as it filters out much of the high-contrast light, especially when photographing backlit race cars.

Additionally, polarisers also enhance the image’s overall appearance by increasing the contrast and saturation of the sky, clouds, and other elements in the background, which can add depth and interest to the shot.

What Is A Polariser

A polariser (also known as a polarising filter) is an optical filter that you attach to your camera lens that is used to block or allow light waves to pass through in a specific direction. The filter is typically made up of two elements. One layer of polarising material that can be oriented in a certain direction to control the direction that the light passes through the lens. While the second layer is purely to mount the filter to the lens.

Also referred to as a CPL or Circular Polariser, you can control the direction of the polarisation by rotating the front element of the filter.

How Does A Polariser Work

Without going into a full science lesson as to how light works, it essentially moves in waves. What a polariser does is filter out light waves that are vibrating in certain directions while allowing light waves that are vibrating in other directions to pass through.

When light waves enter the polariser, they encounter a layer of polarised material that is aligned in a specific direction. This only allows only light waves that are vibrating in a specific plane to pass through while blocking light waves that are vibrating in other planes. This effect can be adjusted by rotating the filter to affect the direction in which the incoming light waves are polarised.

What it means in terms of photography is that reflections and glare, particularly from glass and asphalt, can be reduced and often eliminated from your photos. The effect of the polarisation also often leads to enhance saturation and contrast of colours in your photos, making them pop more.

When Should You Use A Polariser

There are several reasons to use a polariser when photographing motorsport. Obviously, we’ve already covered that they reduce or eliminate reflections and glare but let’s delve into the scenarios when they come in particularly handy.

Starting with sunny days. In bright sunny conditions, you are going to get a heap of reflections, off the cars, off the track, off everything. Using a polariser helps control these to ensure that you get a clearer and more evenly lit photo. Even when shooting into the sun.

Polarisers also come in handy when shooting through fences. By reducing the amount of light making it to your sensor, a polariser will allow you to use a wider aperture, especially in bright sunny conditions to help blur the fence out of the image. Also, removing any glare coming from the fence can reduce the overall impact of shooting through a fence on the final photo.

Photographing through windscreens is another key reason for using a polariser. In categories of motorsport where the car is enclosed with a roof, there can be a disconnect between the car and the driver in your images. By using a polariser to cut through the reflections of the windows of the car, you can allow a glimpse inside to see the driver and creatively capture another part of the story of the race weekend.

I will mention that this doesn’t work in all cases. Some cars, that have particularly curved front windows, particularly prototypes and Porsche’s, the curvature of the windscreen doesn’t allow the polarisation to cut out the glare fully; just helps reduce it.

Polarisers also come in handy on overcast days. While they may not help the colours to pop in the same way as they do on sunny days, they still take the glare and reflection out of race cars helping the overall quality of the image. Just monitor the light; if you find you are pushing your ISO too high, then taking the polariser off will open up two stops of light getting to your sensor.

What Are The Two Types Of Polarising Filters For My Lenses?

Polarisers, or CPLs, come in two varieties screw-on and drop-in. Which ones you need will depend on the lenses that you have.

In most cases, when you are starting out, you’ll be using screw-on filters which are the most common type of polarising filter and are designed to screw directly onto the front of the lens. In most cases, screw-on polarizers are easy to attach and remove, but it might be worth also checking out my how to remove stuck filters post, just in case.

The size of the filter (or filters) you need to buy will be dependent on the diameter of the front element of your lens. On Canon lenses, this is easy to find; it’s with the rest of the lens information near (or next) to the front element. On their top tier “L” glass it’s next to the red ring. But it’s always signified by the following symbol: ø  – the geometric symbol for diameter.

On Nikon’s Nikkor lenses, the placement of the information is a little less consistent. But again, you are looking out for the ø symbol.

While on Sony’s lenses, the information is typically around the outside of the lens’s front element, with the filter size again signified by the ø symbol.

When it comes to third-party lenses like Tamaron and Sigma, I’m not 100% sure, but again the ø symbol is what you need to look for.

If you use a “big” lens, you’ll need the second type of filter, a drop-in. These are typically reserved for those larger lenses like the 400mm f2.8, where the front element size is just too big for a screw-on filter. Drop-in filters are normally mounted within the lens and, as such, need to be purchased from the manufacturer of the lens you own.

In terms of functionality, both screw-on and drop-in polarizing filters work in the same way, but the choice between a screw-on and drop-in polarizer ultimately depends on the camera setup you are using.

Other Things To Know About Polarisers

While we’ve already covered quite a lot about what polarisers are and how to use them. There are a few more things that you should know.

Exposure

As I mentioned briefly earlier, polarisers can reduce the amount of light entering the lens by about 1-2 stops, which can affect your overall exposure. While this typically isn’t an issue in bright sunshine, it can definitely catch you out in changeable light conditions or as the sun starts to set.

Autofocus

When using a polariser, remember you are adding extra elements of darkened glass to the front of your lens. While most cameras can account for this, it can have an effect on how accurately your camera’s autofocus system works, particularly in low-light conditions. If you find you are struggling to nail your focus, you might need to remove the filter or switch to manual focus, depending on what you are doing.

Using Multiple Filters

This is more for video shooters, but if you’re using a polariser in combination with another filter, such as a neutral density (ND) filter, you may need to adjust your exposure settings accordingly. Additionally, stacking filters can result in unwanted vignetting or distortion. As a general rule, I tend to avoid stacking filters.

Care And Maintenance Of Polarisers

Polarisers should be handled carefully to avoid scratching or damaging the filter. Typically they come in a protective case; just carry those around with you when you are trackside in case you need to take them off while you are out shooting. They’ll also help avoid putting fingerprints or smudges on the filter that can affect the quality of your images. It might also be handy to keep a soft lens cloth with you to clean both the filter and the front of the lens. Dust and dirt are all part of photographing motorsport.

Conclusion

Overall, adding a polariser (or several) to your kit will have a huge impact on your motorsport photography. Not only improving the quality of your images by reducing glare and enhancing contrast and saturation but also allowing you to shoot the action from different angles and not be limited by the direction of the light.