General
Circular vs linear polarizer: difference simply explained
Polarizing filters are available in two options: linear and circular. They both help reduce glare, enhance colours and add depth to your photos. What’s the difference and which one should you use for your camera, a circular or linear polarizer, you will find out in this blog.
How polarizer filters work
To understand the difference between circular and linear polarizers, you first need to know how they interact with the light. When light reflects off surfaces like water, glass or even leaves, it vibrates in a particular direction and becomes polarized. This polarization is what causes glare and reduces the colour intensity in your photos.
Polarizer filters help by blocking certain light waves from reaching your camera’s sensor. When you attach a polarizer to your lens, you can control how much-polarized light gets through, cutting down glare and enhancing the natural colours of your scene. Both circular and linear polarizers achieve this effect, but they do so in slightly different ways.
Key differences between circular and linear polarizers
While both types of polarizers serve the same function, their structure is different as well as the way they modify the light waves.
Linear polarizers do linear polarization and consist only of one layer. However, because the light remains polarized in a single direction, it can confuse your camera's autofocus and metering systems. Those systems are perpendicular to the camera sensor and, therefore, the incoming light gets crossed-polarized. This makes linear polarizers more suitable for older manual cameras where autofocus isn't a concern.
Circular polarizers were developed later to solve the problem of possible cross-polarization in digital cameras. They consist of a linear polarizer and a quarter wave plate that twists the light waves back into a circular pattern. This design allows the camera's autofocus and metering systems to work correctly, making circular polarizers compatible with most modern cameras.
Circular polarizer: the most versatile option
A circular polarizer is the go-to filter for most photographers using modern digital cameras. That's the safest option since it doesn't let the polarized light interfere with your camera's autofocus or metering systems. When you rotate the filter, it adjusts the amount of polarization, allowing you to control the intensity of the effect. They are also compatible with old cameras that work with linear polarizer.
Circular polarizers create exactly the same visual effect as linear polarizing filters because they actually contain the linear polarizer inside.
Linear polarizer: does it still make sense?
Linear polarizers are mostly used in film photography with manual cameras where autofocus and complex metering aren’t an issue. Overall, linear polarizers can still be useful in specific scenarios where the photographer has full control over the camera settings.
They are not as popular as circular polarizers for compatibility reasons but you can still find linear polarizers on the market and usually, they are cheaper than circular polarizing filters.
How to understand if the filter is a circular or linear polarizer?
If you already have a polarizer and doubt whether it’s circular or linear, you can check it in a matter of seconds. Linear polarizer works in both directions, regardless of what side of the filter you put. The circular polarizer works only in one direction because of how it’s built. Just check if the filter works from one or two sides.
Circular vs linear polarizer for mirrorless cameras
While you can technically use a linear polarizer with a mirrorless camera, it might cause issues with autofocus and metering, just as it does with DSLRs. If you're using a manual focus mode and have a specific need for a linear polarizer, it can work, but it’s not an optimal solution.
A circular polarizer is still the best option for most mirrorless cameras. Since mirrorless systems rely heavily on electronic viewfinders and autofocus systems, a linear polarizer can interfere with these functions. The circular polarizer, on the other hand, allows the camera to accurately meter light and focus, providing you with the best results.
Circular vs linear polarizing filter: Quick comparison
To make your decision easier, here’s a quick comparison between circular and linear polarizers:
| Feature | Circular polarizer | Linear polarizer |
|---|---|---|
| Camera compatibility | Works with modern digital cameras, autofocus, and metering systems | Best for older, manual cameras |
| Image quality | Excellent for reducing glare and enhancing colours | Also good, but may interfere with metering and autofocus |
| Price range | More expensive due to the additional layer | Typically cheaper |
| Ease of use | Easy to use with modern cameras | Requires manual settings |
| Use cases | Landscape, water reflections, general outdoor photography | Film photography, controlled manual settings |
Circular or linear polarizer – the choice depends on your camera!
Both circular and linear polarizers are used in photography. If you’re using a modern digital camera with autofocus and metering systems, a circular polarizer the best choice. It’s versatile, easy to use, and highly effective in a wide range of scenarios. If you’re shooting with a manual film camera or have specific needs that don’t rely on autofocus, a linear polarizer might be the option, especially if you’re looking for a budget-friendly option.
At Kase, we offer a wide range of high-quality circular polarizers for all camera types. Find the best polarizer for yourself!