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Camera Lens Accessories

What is a CPL Filter?

August 9, 2023 by

In the realm of photography and cinematography, the right equipment can transform an ordinary scene into a captivating visual narrative.

Among the array of tools that wield such transformative power, Circular Polarizer (CPL) filters stand as unassuming yet essential gems.

In this guide, I’ll be diving into everything you need to know about CPL filters.

Let’s dive in!

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Table of Contents

What Is The Definition Of A CPL Filter?

A CPL or Circular Polarising Lens Filter, not unlike sunglasses for your camera, is an optical accessory used in photography and videography to control and modify the light entering the camera lens to manage certain tricky lighting situations.

It consists of two pieces of glass mounted in a rotating frame, which allows the user to adjust the orientation of the filter.

Imagine you’re at the beach on a sunny day, and sunlight is bouncing off the surface of the water—creating glare—or the sky is just too bright.

Or you’re trying to capture the rich color of a landscape, a magnificent forest, let’s say, but the colors are too washed out due to the intense light.

This is where a CPL filter comes into play.

Now picture, if you will, putting on your polarized sunglasses. Suddenly, the world transforms— no more squinting against the glare off the water, and the colors all around you seem richer, deeper, more alive.

That’s pretty much what a CPL filter does for your camera lens.

It reduces those pesky reflections, mutes overly bright skies, and enhances the color saturation and contrast, giving you a much better image quality.

Now this isn’t to be confused with an ND or Neutral Density filter, which just dims the light without messing with the colors.

CPL is like ND plus—it blocks the intensity of light and also tweaks the color and contrast.

To fully enjoy the perks of a CPL filter, it’s not just plug and play.

It would be like learning to play a new musical instrument; you need to play around with it, find out how it works under different light and colors until you learn to make it sing.

Importantly, keep in mind the sun’s position because the CPL filter gives the best results when the sun is to the side, not directly in front or behind the subject.

Bottom line, if you’re into outdoor or landscape photography, this could be your secret sauce to crisp, vibrant, and visually stunning photos.

It might be a bit trickier to use, requiring adjustments to exposure due to the filter decreasing the light by about one stop, but the results can be incredible.

cpl filter in hand
CPL filter in hand

How Does A CPL Filter Work?

Well, imagine a CPL filter, or Circular Polarising Lens Filter, as sunglasses for your camera.

You know how sunglasses can prevent blinding light reflections, make your surroundings appear more vibrant, and aid you in appreciating those beautiful cloud formations in the overly bright sky?

That’s exactly what a CPL filter does for your camera.

It works by darkening overly bright skies, reducing reflections, and cutting out glare from shiny surfaces like water bodies, all while enhancing color saturation.

Imagine this – you want to photograph a beautiful lake surrounded by colorful autumn trees.

But when you look at your photograph, instead of the lovely red and orange hues of the trees, you see a bright white glare reflected off the water.

Enter the hero of this story, your CPL filter, which cuts out that obnoxious glare, allowing the natural colors around the gleaming lake to shine through.

cpl filter comparison
CPL filter comparison

Now this magic tool isn’t going to do wonders everywhere. They’re particularly useful for landscape photography as they assist in eliminating unwanted glare and reflections from shiny surfaces.

Imagine trying to photograph the enchanting Grand Canyon, but the sunlight reflecting off the playful Colorado River is spoiling the shot.

Your trusty CPL filter can come to the rescue and eliminate that reflection.

Remember, circular versions of polarizing filters are preferred due to their flexibility. With a CPL filter, you’ll essentially paint with light.

However, you’ve to be cautious, as some types of polarizing filters can impact a photo’s brightness, requiring longer exposure times.

It’s a bit like driving, you control the speed depending on the terrain and traffic to ensure a smooth ride.

Likewise, while controlling the light with a CPL filter, you must adjust the exposure to compensate for the decrease in incoming light.

So, in a nutshell, a CPL filter is like your very own magic touch that intensifies colors, removes reflections, and gives your photographs an amazing quality under the right conditions.

What Are The Different Types Of CPL Filters?

What are the different types of CPL filters? This is definitely something interesting to explore.

The truth is, whenever you are talking about CPL filters, most people generally refer to circular polarizing lens filters, because they indeed rule the roost due to their convenience and versatility.

These are the ones you’re likely to encounter in a professional photographer’s bag.

An interesting way to look at it is like this – CPL filters are like the different shades of sunglasses you wear.

Just as your sunglasses can have different tints and polarizing effects to protect your eyes and help you see better in various lighting situations, CPL filters can vary in how they affect the color and contrast of your images.

different types of filters
different types of filters

Multi-Coated CPL Filters

For instance, there are multi-coated CPL filters that have additional protective layers on them to prevent damage from moisture, dirt, or scratches.

They are like that sturdy pair of sunglasses you just can’t do without on a beach day.

Low-Profile CPL Filters

Then, there are low-profile CPL filters that are ultra-thin to avoid any risk of vignetting.

They could be compared to those sleek, designer sunglasses you put on when trying to leave a fashion statement.

There are also multi-coated low-profile filters.

Warming CPL Filters

Lastly, you might also find warming CPL filters that come with a ‘warming’ effect.

They add a bit of warm color cast in your photos, like the cool tinted sunglasses that you put on for that dreamy sunset vibe.

Remember that the effectiveness of a CPL filter varies with the sun’s position in the sky. It’s like altering your position with respect to a light source to reduce the glare in your eyes.

While choosing a CPL filter, just like picking the right sunglasses, it’s important to consider what you need it for.

Practice and experiment with the ones you have, and over time, you’ll develop a keen sense for which one delivers the best results in any given situation.

And of course, while CPL filters do decrease the amount of incoming light, thus requiring exposure adjustments, the impact they have on enhancing colors, removing reflections, and ultimately, elevating the quality of your photographs are incredibly significant.

They’re definitely a worthwhile addition to any photographer’s toolkit.

How To Use A CPL Filter?

So now that you know everything about how a CPL filter works, how do you use one?

1. Practice and Experiment

Well, to effectively use this tool, you need to practice and experiment, just like learning to ride a bike.

You know how when you learn to bike, you have to get a feel for the brakes or to operate the gears?

It’s something similar here.

Your first few clicks might not be the masterpieces you envisioned, but tweaking the CPL filter involves an element of trial and error until you get that “just right” shot you aimed for.

2. Understand Light and Direction

Using a CPL filter also involves understanding light and its directions, like a game of pool where the angle of the cue ball affects the motion of the target ball.

When you’re using a CPL filter, the sun is your cue ball.

The impact of the filter can vary based on the sun’s position, and you would notice the maximum effect when the sun is to the side.

So get into the habit of observing the sun and its position before taking a shot.

Keep in mind that CPL filters would decrease the amount of incoming light by about one stop. Imagine your camera is like a pupil.

When there is a lot of light, it contracts.

The CPL filter is like adding another shield to stop some light from entering, making the image a bit dimmer than normal.

It’s like squinting to look at something in the harsh afternoon light.

Therefore, you may need to adjust the exposure accordingly- just as you would adjust to changing light conditions at different times of the day.

All this might sound a tad technical now, but as with any tool or technique, mastery comes with practice.

I assure you, the addition of a CPL filter on a bright sunny day or for a landscape shot with water bodies would make a world of difference.

Just like the cherry on the top of your favorite sundae!

I hope I’ve made the usage of the CPL filter a bit clearer to you. But the real fun begins when you start experimenting. So get your gear ready and start clicking!

What Are The Advantages Of Using CPL Filters?

What are the advantages of using CPL Filters, you ask?

As mentioned, just as your sunglasses cut down the glare, enhance colors, and help you see clearer on a sunny day, CPL filters work similarly for your camera.

1. Reduce Reflections

When you’re out shooting a landscape, sometimes the sky can appear overly bright, or you get these unavoidable reflections blemishing the natural beauty of the water bodies you’re trying to capture.

CPL filters work like a charm here, darkening that too-bright sky and reducing those pesky reflections.

Basically, it’s like turning down the brightness of the sun.

2. Enhance Color Saturation

CPL filters also enhance color saturation, which is a fancy way of saying they make the colors in your photos pop.

Ever seen those stunning photos where the blue of the sky and the green of the grass seem more vibrant than reality?

Yeah, that’s because a CPL filter was likely used.

But here’s where it gets cool – CPL filters don’t just block light, like Neutral Density filters do, but these guys can also alter color and contrast.

Remember those Instagram photos where a boring old duck pond turned into a magical mirror, reflecting scenery with vibrant colors and deep contrast?

That was probably a CPL filter working its magic.

You might think, why not just use a filter on your laptop during post-production and save the hassle?

It’s like using Photoshop to put a hat on a photo of yourself – sure, it can look alright, but it’s never as realistic or as satisfying as when you’re wearing an actual hat right from the start.

Are There Any Disadvantages Of Using A CPL Filter?

Are there any disadvantages of using a CPL filter? Well, my friend, while CPL filters are great tools that come with a variety of advantages, there are also a few downsides you should be aware of.

1. Decreases Amount of Light Entering Lens

Firstly, one downside is that CPL filters decrease the amount of light entering the lens by about one stop.

This means, in low light conditions, a CPL filter can add to your problems.

Just as closing the curtains reduces the light in a room, the CPL filter blocks some of the incoming light in your camera, leading to darker images.

This might require you to adjust the exposure time, aperture, or ISO, kinda like turning on more lights or opening the curtains wider to offset the darkness.

2. Can Lead to Uneven Colors

Also, the polarizing effect can sometimes lead to uneven colors in your photos, especially if you’re shooting with a wide-angle lens or against a wide sky.

It’s a bit like how a painter might see their painting change based on where their light source is coming from.

Moreover, CPL filters can alter color and contrast, which is usually a beneficial thing, but can occasionally lead to unwanted effects.

Say you’re trying to capture a bright, vibrant rainbow against a dark sky – a CPL filter might just make that rainbow disappear as it tends to reduce the brilliance of some colors under certain light conditions, akin to how sunglasses can make some colors less vibrant.

3. They Aren’t Cheap

Lastly, CPL filters don’t come cheap.

So, before going for one, ensure you really need it, just like how you’d evaluate your need before purchasing any high-end product.

So, while CPL filters are extremely helpful in certain situations, especially for outcomes you desire, like darkening a bright sky or reducing glare from surfaces, remember that they do come with their share of challenges.

As with any tool, it’s essential to understand when to use it and when not to.

Just like our favorite cooking gadgets, they’re amazing helpers but only if used correctly and for the right dish.

Keep practicing and experimenting with your CPL filter for best pictorial results.

What Should You Consider When Buying A CPL Filter?

What should you consider when buying a CPL filter?

1. It Requires a Bit of Experimentation

Learning to use a CPL filter effectively does require practice and experimentation.

It’s a bit like learning to adjust your sunglasses until the scene in front looks just right.

Just like how sunglasses work better under certain light conditions, CPL filters work best when the sun is to the side – don’t forget how we noticed the sun’s position can change your shot dramatically.

Also, they decrease the amount of incoming light by about one stop which influences your image’s brightness.

Think of it as dialing down the brightness on your phone screen, you might need to adjust the ‘exposure’ setting in your camera to make up for the loss.

2. There are Different Types

Another thing to remember is that there are many types of polarizing filters, and the circular ones are generally preferred due to their versatility.

It’s like comparing a Swiss army knife to a normal knife in your kitchen – both are useful, but one simply does more!

Some types can even impact the brightness of your photo, which could require longer exposure times.

In the end, remember that CPL filters can majorly enhance your outdoor photography, especially landscape shots.

It’s like the magic ingredient in our favorite dish, it intensifies the colors, removes those pesky reflections, and overall, improves the image quality.

It’s like upgrading to HD in your favorite show!

Can CPL Filters Be Used With All Cameras?

By design, CPL filters can be used with pretty much any camera, as long as you can adapt them onto the lens.

But, it’s not as simple as popping one onto your lens and expecting magical outcomes.

Think of a CPL filter as a tool in your toolkit.

Like a wrench can’t be used for every repair job, a CPL filter isn’t appropriate for every shooting situation.

Let’s say you’re capturing a birthday party indoors. In that case, a CPL filter might not be your go-to tool, as they decrease light intensity by about a stop.

This might necessitate a bump in your ISO or a decrease in your shutter speed, which might not be ideal for your specific shooting situation.

This is similar to how you wouldn’t use a hammer to unscrew a nut, right?

Also, as you know, cameras aren’t created equal.

For DSLRs and system cameras, where you have interchangeable lenses, a CPL filter can be a great addition to your gear.

On these cameras, the lens diameter can be matched with a corresponding CPL filter, similar to how different sockets need different sized wrenches.

Mobile and under-water cameras, however, might require specialized adaptors or housing to fit a CPL filter on them.

It’s like trying to fit a circular peg in a square hole-possible, but you’ll need an adapter.

But ultimately, what matters is that you experiment with the CPL filter, similar to how you practiced with your shiny new screwdriver.

It matters less which camera you’re using and more how you apply and master the filter.

To summarize, a CPL filter can be used with any camera, as long as you have the appropriate adapter or housing, and are using it in a suitable atmosphere.

Think of it as one more tool in your photographic toolbox.

It’s not the answer to everything, but when used correctly, it can significantly enhance your photo quality.

Just like you wouldn’t build a house using only a hammer, don’t build your photographic career around just one accessory or technique.

What’s The Difference Between CPL Filters And Other Filters?

What’s the difference between CPL filters and other filters, you ask? We’ve touched on this a bit in the previous sections, but let’s take a closer look.

The critical difference here is that unlike Neutral Density filters (ND filters) that simply dim the world, so to speak, CPL filters, short for Circular Polarising Lens Filters, do substantially more.

They block light, yes, but they also have the power to alter color and contrast.

It’s like the CPL filter is an artist, adding depth to a scene by enhancing its colors and contrasts while an ND filter merely dims the lights in a theater.

Now, let’s take a closer example. Imagine yourself wearing sunglasses on a bright, sunny day. These sunglasses are your typical ND filters that reduce the overall brightness.

Now imagine glasses that not only dim the brightness but also remove the nasty glare off surfaces and enhance colors around you.

These glasses would be the CPL filter.

Hang around any landscape photographer’s neck, and you will find CPL filters as these are specifically beneficial for landscape photography due to their ability to eliminate unwanted glare from reflective surfaces, like say, a calm lake or a smooth metallic surface.

And that’s not all! They also heighten color saturation and influence photo contrast based on lighting situations.

It’s like adding something extra – dynamism, if you will, to their landscape shots.

How To Clean And Maintain Your CPL Filter?

So, you’re asking how to clean and maintain your CPL filter, right?

It’s imperative to keep your CPL filter clean and maintained as its performance directly influences the quality of your images, much like how the cleanliness of your car’s windshield determines how clearly you see the road.

The cleaning process is relatively straightforward and requires just a few items: a microfiber cloth, a lens cleaning solution, and a blower, if available.

It’s similar to cleaning your eyeglasses properly to ensure the best vision possible.

Start by blowing away loose dust, using a blower if you have one.

Remember, just like a gentle wind removes leaves from a sidewalk, this step helps you get rid of any loose particles that could potentially scratch the filter when you wipe it.

Be gentle and patient.

Next, apply a few drops of the lens cleaning solution to the microfiber cloth. It’s like applying conditioner to your hair; you don’t want to pour it straight onto the filter.

Then, wipe the filter gently in a circular motion. Why circular? Well, just as our moms taught us to wash dishes with circular movements for best results, the same applies here.

Never use tissue paper or your shirt for cleaning. It’s like using a sandpaper to scrub a non-stick pan. You’ll risk scratching the filter’s surface.

In terms of maintenance, when not in use, keep your filter in its case to avoid damage, just as you would store your precious vinyl records in their sleeves to keep them from getting scratched. Make sure the case is clean too.

Remember to be consistent. This isn’t a one-off event. It’s like brushing your teeth. You can’t do it just once and forget about it.

If you take care of your CPL filter, it will take care of your photography.

What Are Some Popular Brands Of CPL Filters?

Some popular brands of CPL filters, you ask?

Well, there are quite a few in the market, but renowned brands that photographers often turn to include Hoya, B+W, Tiffen, and Lee Filters.

Let’s delve into each one, kind of like different types of coffee at your favorite cafe, with each having its unique roast and flavor.

Hoya

Hoya, for instance, is like your classic black coffee; it’s reliable and long-standing in the field.

The Hoya HD3 is particularly a favorite among many because of its amazing light transmission abilities, ensuring your photos won’t lose that crucial detail.

B+W

Now, B+W is like an artisan roast, with filters like the B+W Kaesemann being highly acclaimed for its high color accuracy and consistency, not to mention its excellent hydrophobic and anti-reflective properties.

It’s like getting that intense flavor in your coffee, really brings out the authenticity of the beans.

Tiffen

Compared to these, Tiffen is more like a good old comforting cappuccino.

Filters like the Tiffen Digital HT perform exceptionally in terms of color neutrality and reducing unwanted reflections.

Not the fanciest, maybe, but it gets the job done just right.

Lee Filters

Finally, Lee Filters, specifically the Lee Filters Landscape Polariser, can be compared to that unique coffee blend your barista recommends. Designed specifically for landscape photography, this filter reduces glare, enhances colors and can rotate independently of your grad filters, giving you that edge in creating your perfect shot.

So, just like finding your favorite coffee, it’s all about experimenting with CPL filters of these various brands to see which brings out the best in your photography style.

Is A CPL Filter Necessary For Professional Photography?

Is a CPL Filter Necessary for Professional Photography?

While a CPL filter isn’t exactly “necessary,” it’s like an ace up your sleeve.

It enhances colors, removes reflections, and ultimately boosts image quality, elevating your outdoor photography to new levels.

So try it out, experiment and see how it works for you. Photography is all about pushing your boundaries, after all.

Frequently Asked Questions

What is the difference between a polarizer and a CPL filter?

A polarizer is a general term for a filter that polarizes light, while a CPL (Circular Polarizer) filter is a specific type of polarizer that is designed to work with modern cameras and auto-focus systems.

What is the difference between CPL and ND filters?

A CPL (Circular Polarizer) filter selectively reduces reflections and enhances colors, while an ND (Neutral Density) filter uniformly reduces the amount of light entering the lens without affecting color, primarily used for controlling exposure and achieving creative effects.

Can you leave a CPL filter on all the time?

While you can technically leave a CPL (Circular Polarizer) filter on your camera lens all the time, it’s recommended to remove it in situations where the polarizing effect is not needed to avoid potential reduction of light and image quality in certain conditions.