Neutral density (ND) filters and polarizing filters are often confused to do the same thing but they are actually quite different and serve two completely different purposes.
The misconception may have occurred since polarizing and ND filters are two of the most commonly used filters in the field of photography. However, the only similarities they share are to help manage challenging light conditions and some design features - that being an augmentation tool made of a special coated protective glass that you flip onto your camera lens to get the most out of your shot.
Once you understand what they are meant to do and how to use them correctly, you will see how they can each enhance your photography in different ways and even inspire you creatively as a photo artist.
Let’s look at what each of these filters has to offer by sizing up ND filter vs. polarizer, and give you some great recommendations from our collection to help you achieve some fantastic results when taking pictures.
What Is A Polarizing Filter?
A polarizing filter or ‘polarizer’ is a single glass element that you fit onto the camera lens to control reflections and glare on images typically caused by bright sunlight. In addition to this, they also increase the color saturation and contrasts of images so they appear vibrant and vivid.
A more popular type of this filter is what’s known as a circular polarizer (CP), which incorporates two separate optical glass elements in a single unit. The front glass element of the CP rotates to control light exposure to offer more flexibility and control over your photography. Our QuartzLine Circular Polarizer filter for example is particularly designed for landscape photographers in the field, allowing them to seamlessly control light reflections on several types of objects in a scene. It is especially useful in landscape compositions featuring water, snow, ice, blue skies, and foliage by way of bringing out the natural color saturation of these objects while darkening the sky to remove reflections, and reducing unwanted glare from the scene.
What Is A Neutral Density Filter?
ND filters on the other hand will not affect the color of an image but instead manage the brightness or light intensity levels caused by the sun. The other significant and most spectacular thing about these filters is that they slow the camera’s shutter speed to produce creative motion blur effects on moving objects in a scene.
ND filters can be circular or square in shape and either screw directly onto your lens or are used in combination with a filter holder that installs to the front of the camera. They are engineered with a neutral tint or coating, each of varying densities denoted by a number system referred to as the ND factor. Each factor incorporates a range of light transmission values called ‘stop’ reductions. For example, our Polar Pro Neutral Density filters range from densities of 4 to 100k, termed ND4 to ND100k. An ND4 has 2-stops while the ND100k has 16.6-stops of light reductions.
ND Filter vs. Polarizer: How are They Different?
By exploring the capabilities of an ND filter and polarizer with the end result they can bring to your photography, you will clearly see the distinction between the two.
As mentioned before, a polarizer focuses on restoring lost or diminished color contrasts and saturation of an image from consequent bright light. It does this by reducing light reflections and glare that are refracted off surfaces when the sun is at its peak levels (late morning and afternoon hours), although reflections do occur when lighting is subdued.
Under similar bright light conditions, the ND filter will allow you to capture photos exactly as they appear without overexposing the shot. They also allow you to shoot using wider apertures and longer exposures, which achieves the element of blurring, so objects that move in the surroundings can look smooth and mystical.
Let’s identify a few standard features in your landscape photography and compare how the ND filter vs. polarizer works to modify their appearances.
How Neutral Density Can Improve Your Landscape Shot
For scenes where there is perhaps a lake, river, or stream, etc. the ND filter will diffract bright sun rays so you can capture objects beneath the surface of a waterscape the way you would if you were looking directly at it with the naked eye. For instance, you can emphasize stones, shrubs, and fish on a riverbed if you’re lucky. All our PolarPro ND filters are made with patented Cinema Series Glass that offers a low refractive index, color neutrality, and perfect target transmission so shots like these come out clear and precise. In the event you select a higher density filter, say an ND 32 or ND 64 to capture water, it forces your camera to focus through a darker tinted filter so then the shutter remains open for longer periods. What happens here is motion is being captured over a period of time so the outcome of running water looks velvety and smooth.
For sky scenes under bright light conditions, the ND filter replenishes the true tones of the sky and helps to clearly differentiate the clouds while capturing their actual formations and structure. Using a high ND filter will slow the shutter speed to eventually blur clouds to look milky and often quite mystical.
Whether it be grass, trees, or leaves, ND filters will give a cluster of foliage the definition it needs to stand out in your shot. Leaves on a tree, for example, are already pretty hard to distinguish especially from a distance, bright sunlight will have an added fading impact but when an ND filter is used, you will be able to reduce glare and reflection to achieve optimum clarity. It works the same to produce a blurring effect for long swaying grass or wind-blown branches.
How A Polarizer Can Improve Your Landscape Shot
Using a CP for water shots will cut down reflections and glare the way ND filters do but the outcome is quite different. So the same way you can capture objects laying on a riverbed as mentioned before with ND filters, since polarizers are colored filters it instead boost the colors of stones, shrubs, etc. for more animated-looking photography. The best time to try using a CP is when your existing scene has pretty colorful imageries that you want to emphasize.
For sky shots, polarizers again give dull-looking blues a pop of color, clouds too get a boost and can appear vivid with more opacity.
Polarizers offer much more clarity to these types of outdoor photos by selectively highlighting different shades of green on trees, plants, and leaves. They add depth to the green contrasts of foliage that extreme light tends to compromise by fully eliminating reflections.
ND Filter vs. Polarizer – Conclusion
Now that you know what these filters can do for your photography, choosing one or the other can help to communicate your work better. Understanding what you want to achieve in your shot can be executed with the right filter and of course, they will allow you to boost your creativity.
Creatives wanting to take their photo art even further can explore our unique Neutral Density + Polarizer (ND/PL) filters that offer the perks of both worlds.