There are many different types of filters out there which can alter the view of the world. Neutral filters reduce the amount of light evenly, like a screen. UV filters reduce the amount of ultraviolet light entering your camera body. Gradient filters allow you to shoot images where there is a great discrepancy in the amount of light in one area of the view, preventing over- or under-saturation. Many of these effects can be imitated with post processing, which is admittedly getting better every day. However, one type of filter whose effects you cannot replicate on the computer is a polarizing filter. This filter is decidedly a favorite among landscape photographers. It is considered essential in their arsenal. Here’s why!
What is a Polarizing Filter?
A polarizing filter restricts the amount of light entering your camera based on the direction from which it is coming. This is different from other filters which more or less uniformly reduce the amount of light of a certain wavelength (or range of wavelengths). Because the resulting image your camera sees is dependent upon your location relative to your subject as well as to every light source present, it’s nearly impossible to recreate the effects through post processing.
Polarizing filters only allow light coming from a certain direction to reach your camera. This greatly reduces the amount of ambient light reflecting off various surfaces. The result is an increase in color saturation and contrast. Your images look less hazy and have more pop. One of the common frustrations with landscape photography is that the sunlight bouncing around has a dampening effect on the vibrancy of an image. Polarizing filters help mitigate this, which is why landscape photographers consider them a must-have.
Take a look at the before/after image below. This shows you how great an effect a polarizing filter can have on your image — even just a standard, run of the mill shot of your car in your driveway. I’ve left the camera on auto mode and the only difference between the two images is that the image on the right was taken with the use of a polarizing filter. Notice how the reflections on the windshield have been greatly reduced. Shine on the car body has been mattified. And the wet ground in the background doesn’t produce as great a sheen.
Maximum Degree of Polarization
Because polarizing filters work by restricting light coming from a specific angle, the strength of their effect is dependent upon the angle you are shooting at compared to the source of light you are attempting to eliminate. When shooting landscapes, this is almost always going to be the sun. The maximum degree of polarization is achieved when your camera is aimed perpendicular to your light source.
This means that shooting straight ahead with the noonday sun above you, or shooting upwards or downwards during low sun at sunrise or sunset, will result in the greatest polarization effects. A handy technique to use is to point your index finger straight at the sun, with your thumb stuck straight up. By rotating your wrist and keeping your index finger pointed at the sun, your thumb will move along the plane with the greatest impact. If you aim your camera along this plane, the effect of your filter will be its strongest.
The Best Uses for Polarizing Filters
Reducing or Eliminating Reflections
Since polarizing filters reduce light coming based on their direction, they allow you to reduce or eliminate unwanted reflections. This is true of all surfaces and will make transparent surfaces such as water or glass appear more transparent. Those images where photographers capture a lake where you can see through to the contents within? They’re using polarized filters to help reduce the reflection of the sun on the water surface!
The effects of eliminating reflections are applicable everywhere. You can see through the clear water better. You can eliminate glare coming from a window, or one someone’s glasses. Undesirable highlights can draw attention to the wrong parts of a frame, and by using a polarizing filter you can guide attention back to your intended subject.
Hazy skies are a result of ambient light reflecting off of minuscule particles in the atmosphere. What looks like a brilliant blue to your eyes may be captured in muted color by your camera. By reducing the amount of ambient light entering your camera, your images will be less affected by hazy skies. This often leads to bluer skies with colors that pop!
Of course, polarizing filters aren’t a magic cure-all. They can’t turn a hazy, polluted city center into a clear oasis. But they can get you as close as possible given the circumstances. Take a look at this mountaintop view which spread over miles. It is greatly sharpened by a reduction in ambient light because of the use of a polarizing filter. You’d be amazed at what a difference in clarity a thin piece of coated glass can make to an otherwise perfect photo.
Color Enhancement and Increased Contrast
Just as hazy skies are reduced with polarizing filters, subjects will also have better-defined contrast. Colors will seem enhanced, straight out of the camera. This is because the ratio of diffuse light to ambient light has increased. Objects will appear closer to their true color. This benefit, of course, is not restricted to just landscape photography.
Polarizing filters can also help define clouds in your shots, as oversaturated sections of cloud become more discernible. Because of how they can make landscapes pop, they’re a great way to define nature. When thinking about evoking emotion in your landscapes, consider a polarizing filter!
Things to be Wary of When Using Polarizing Filters
Creating Unnatural Skies
Because polarizing filters work based on the direction of the light, wide angle lenses which capture a greater angle of view can highlight the effects of changing degrees of polarization. If using a wide angle lens, you may notice that the blue sky shows up with a well-defined gradient. When angled incorrectly, you may end up with the sky a dark blue in the middle, and a gradient which clearly increases and then decreases again going across your view.
To mitigate this, you can set the maximum degree of polarization to occur on an edge (or better yet, a corner) of your shot. This reduces the likelihood that your wide angle captures enough real estate to show the gradient reversing again.
Proper Alignment Requires Effort
The effects of polarizing filters can be difficult to discern through the viewfinder. If you’re using a digital camera you’re in luck, but regardless, it takes time to consider the relative positions of your subject, camera, and light source. Since polarizing effects are not imitable after the fact, it’s important to get this right in the field — and the conditions will change with every shoot you do.
Common Filter Drawbacks
Like all filters, polarizing filters reduce the amount of light entering your camera, sometimes by up to two or three stops. You will need to take longer exposures, and this can create trouble in situations where light is already low. Compensate with tripods, or by increasing your aperture, if necessary. For many daylight landscape photographers, this won’t always have a terrible impact.
They can also cause vignetting since they add to the length of your lens tube without increasing the width.
They are Expensive
Since polarizing filters require precision in craftsmanship, and their effects cannot be replicated properly via post processing, they can cost a fair bit more than most other filter types. However, they add quite a punch to your photography kit! If the price isn’t a huge factor, I would strongly recommend in investing in one.
They Can Limit Your Creativity — If You Let Them!
As with everything in life, if you let your tools define your way of thinking, they can rule your decisions. Don’t let the hammer in your toolbox turn everything into a nail!
Polarizing filters may have a devoted following in landscape photographers, but that doesn’t mean that every landscape shot benefits from their effects. Sometimes reflections can add a lot of depth to an image. If you are photographing a waterfall or wet rocks which are reflecting light, a polarizing filter can reduce the reflections in a way that make the image seem flat. Depending on the feeling you are trying to evoke, allowing reflections to permeate your shot may be the better choice. And in low light settings, you must always consider the trade-offs between adding another filter to your lens or not.
Polarizing filters can greatly up your photography game. But like all pieces of equipment, they’re just another tool in your box. Your greatest asset will come from you and your unique decisions on what to use, and when to use it!
We hope you enjoyed reading about polarizing filters and their importance. If you do decide to give one a try, please do post your sample photos in the comments area below.
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