Knowing my CPL can create dark areas of the sky, I used that purposely when taking this image. By rotating the polarizer to darken the sky as much as possible, it creates these rich blue tones that separate the sky with the foreground. When I got into Lightroom and converted to black and white I was able to create extreme contrast between the foreground and background. I talked about this editing technique briefly in a video I made about Lightroom.

Damn! Although not my personal fav channel, I never thought of them as that bad... This one though, this was bad ... and the B+W infomercial cuts, c’mon

There are downsides and precautions to using a CPL but they are few and far between. Polarizers do cause a bit of light loss, roughly about one to two stops depending on the polarization intensity. Thus, if you are trying to shoot handheld, you might have to shoot without one if there isn't enough ambient light.

Given the choice to bring one accessory when shooting landscapes, it absolutely needs to be a circular polarizer and this is why.

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That is the lens I shot a lot of these photos on! I can't recommend a CPL enough, if the article didn't make that clear hehe :)

To calculate the Critical Angle, first determine the N.A. (Numerical Aperture).The N.A. of any glass combination may be calculated as follows: (where N1= the index of refraction of the core glass), and N2=(the index of refraction of the cladding glass):

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Calculating the N.A. for the 45 degree angle (B) of incidence yields .38 (sin(45/2)). Therefore, fiber with an N.A. of .66 will accept all of the light from the bulb, but the output cone at the other end will be 45 degrees, not the 83 degrees that you might expect. Conversely, the N.A. .25 fiber is not capable of accepting all the light from the bulb. Any light transmitted through this fiber will create an output cone of 29 degrees.

Oh for sure and I thought the article was great as is. I just remember the first time I thought to use a polarizer indoors and was blown away by how much detail i could recover just by rotating my CPL. I'm surprised to hear some people that also work in RE industry that don't use it, but then again removing it every time you shoot a polarized window is kind of a pain. But to each their own I suppose!

Angle A (29 degrees) is the acceptance angle of a N.A. .25 fiber. Angle B (45 degrees) is the incident angle from the bulb. Angle C (83 degrees) is the acceptance angle of a N.A. .66 fiber.

There are many other items you can get away without having, but a CPL does so much you can't replicate otherwise. I cannot stress enough how important it is to have one in your kit. Personally, it’s far more important than any other filter and should likely be on your lens the majority of the time anyway. If this is something you don’t have already, do yourself a favor and get one immediately.

I do use polarizers for people with shine that can't be killed by normal techniques--like me. I'm darker skinned and extremely oily and often sweaty. I've worked on camera a bit, and I know that really good professional foundation (professionally applied) can handle it, but that's a daunting proposition in most retail photography cases, such as an entire family outdoors.

What if you used that dark sky to your advantage? While it might not be the effect you want in some photos, you can potentially use it as a creative tool.

Personally I think a CPL is the best bang for your buck that you can buy to improve your photos in landscape photography. Spend less than $100 and completely open up new worlds of results.

The Numerical Aperture is an important parameter of any optical fiber, but one which is frequently misunderstood and overemphasized. In the first illustration above, notice that angle A is shown at both the entrance and exit ends of the fiber. This is because the fiber tends to preserve the angle of incidence during propagation of the light, causing it to exit the fiber at the same angle it entered. Now look at the figure below, which is a drawing of a typical light guide being illuminated by a projector type lamp.

That said, I see a ton of work from some of the most well known landscapers around that were clearly shooting with a Polarizer.

Metal surfaces don't polarize the light they reflect, so those reflections are not reduced by a "polarized light filter" (to be more accurate).

EW Weisstein · 2005 · 29 — Cylindrical coordinates are a generalization of two-dimensional polar coordinates to three dimensions by superposing a height (z) axis.

I just picked up a Canon 16-35L IS F4 for a trip to Grand Tetons and Yellowstone. I’m going for the wildlife but thought I would probably have time for some landscapes waiting for them, I should look into adding one of theses I like the affects it has on the images above.

Alex Armitage has traveled the world to photograph and film some of the most beautiful places it has to offer. No matter the location, perfecting it's presentation to those absent in the moment is always the goal; hopefully to transmute the feeling of being there into a visual medium.

Many people believe that using a low N.A. fiber will “focus” the light from a wider N.A. source. This is not true. As you see, the lower N.A. fiber simply has a lower acceptance angle. While the resulting output will be projected into a tighter area, the overall light transmitted is less than what might be transmitted through a higher N.A. fiber. To focus light from a source, a lens assembly must be used to gather all available light and change the incident angle (and resulting N.A.) to match, (or be less than) the N.A. of the fiber being used.

Actually I never take CPL from my lens when doing outside portraiture. It makes backgrounds so much more interesting that I can't believe that anyone does portraiture without it ;)

I’d love to know what you think. Do you think there’s anything more important than the circular polarizer as an accessory? Is it more important than the second lens in your bag? Feel free to share some of your favorite shots you couldn't have captured without using one.

The Northrups are very smart and tend to be very good in sussing out technology from the point that they begin studying it. But when they try to "reverse engineer" old concepts without really having studied how those old concepts actually came to be, their reverse engineering is often wrong. That's where I find myself saying, "No, Tony, that is not how that happened."

As this fiber accepts light up to 34 degrees off axis in any direction, we define the ACCEPTANCE ANGLE of the fiber as twice the critical angle or in this case, 68 degrees.

Okay I normally don't have anything bad to say about the Northrups but this was a terrible take on the subject. The example photos are an awful representation of what a CPL does.

I think it's the first item any new photographer should pick up after a camera and lens. I'd even go as far to say to get it before a tripod unless your only wanting to shoot astro or landscapes.

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If you know the input launch angle of the light beam, you can determine the size of the spot when it’s projected from the end of a Fiber optic fiber or component (at any distance) by using some simple trigonometry. If you’re using a collimator, you can also determine the spot size (and the change in the output angle). We’ve made it simple for you! Use our Excel Numerical aperture calculator.

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If you have ever read anything about using a CPL before you will know that cutting out reflections is its most used application. I think many of those articles leave out a key point though, and it’s the ability to manipulate reflections. Yes you can turn a CPL to completely cut out reflections but realizing that it’s more than just an on/off “switch” is key to getting to the next level when shooting with a CPL.

I seldom use polarizing filters but when I do, I use them to cut down harsh reflections on a stream that make exposure really difficult. Too much reflection will cause the rest of the image to be too dark. Over expose and the whites are even more blown out. Use a polarizer to tame the reflections and the rest of the exposure falls into place. It's a miracle.

I'll use one for portraits to cut down on a sweaty or oily face. For some folks, asking them to wash their face just doesn't seem like a good option.

Additionally, (and somewhat confusing) although the law of physics state the angle of incidence must equal the angle of reflection, life will get in the way when light tavels through longer fibers and fiber bundles. Impurities in glass alter the propagation angle over length such that, if the fiber or fiber bundle is long enough, regardless of input angle, the emitting angle will equal the acceptance angle of the fiber in step index fibers.

Tony does bring a few tips and points that some people *should* think about, but I agree with many he does fail to show the upsides of a CPL filter in a way that he should. The video isn't balanced enough.

That said I'd look for some comparisons and reviews. Both Breakthrough and NiSi are great brands to look into! If you need anymore help don't hesitate to ask.

Great article. I would like to say though that the circular polarising lens does not remove all reflections. Only polarised reflections, not direct reflections (as far as I am aware, I am not a pro). Try it out and see what reflections remain and which ones disappear as you rotate the filter. This post is aimed at beginners as they may think all reflections can be removed, but as you see in the lake cabin even the wood panels retain some reflection and elsewhere in the photo.

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For example, taking 1.62 for N1 and 1.52 for N2 , we find the NA to be .56. By calculating the arc sine (sin-1) of .56 ( 34 degrees) we determine THE CRITICAL ANGLE.

This shot was taken using a CPL, but still has a lot of reflection left in the photo. The key here was that I wanted to cut through some of the reflections but not all of them. You’ll notice on the right side of the image you can see through the water enough for the rocks to appear but there’s still enough reflection for the clouds in the sky. It’s in these types of photos where you really start to see the creative power you have in the smallest item in your kit.

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That isn't necessarily true. Having clouds in the sky completely fixes that issue and ideally I want some form of atmosphere in my sky. Sometimes that isn't the case like the image of the boat that I put here where there are clouds and enough blue sky to have that dark sky effect. As Andrzej pointed out, there are ways around it that might be worth the extra effort.

I thought about including more reasons outside of landscape photography. This is definitely a huge reason to own one if you shoot any form of architecture. There are a ton of other practical and real world uses for owning one that I couldn't fit in here.

These are two examples I shot specifically to showcase how much haze you can remove with a CPL. Both of these are completely unedited aside from aligning them in Photoshop (was handholding a 70-200mm lens) and adjusting exposure to match. If you want the scientific explanation of how this is possible, check out these slides from MIT. The quick explanation is that haze is essentially moisture and particles in the atmosphere that reflect light. By using a CPL, you cut out some of those reflections just like when your shooting a lake. There are editing techniques to remove haze from your image but you typically cannot push those very far without the images looking over saturated and muddy.

As stiching panos requires additional work, you can as well do a one swipe with polarizer (for the non-sky elements) and the other one without (just for the sky) and blend them together in post. It requires, of course, an extra 15 minutes in post, but if the result seems worth the effort, then it's a one way to try. :)

Illustrated definition of Linear Scale: A scale with equal divisions for equal values. A typical ruler has linear scales.

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As boring as this example is, it's perfect for representing the saturation you gain from using a CPL. You'll notice the reflections in the water being removed, but pay close attention to the wood in the image. Notice on the walkway that the wet wood creates a small amount of reflection and the CPL cuts right through those reflections to reveal a deeply saturated wood. Also look at the wooden walls of the boat house to see the difference in color and saturation.

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I have a B+W I've used for 6+ years and a newer one that's part of mine Wine Country Camera system. Both are great but I'd suggest reading up on more options to find some comparisons. When I bought my first one in 2011 there weren't as many options.

I know this isn’t related to landscape photography, but I find using a CPL most beneficial for real estate photography when removing glare on shinny surfaces like glass tables and polished hardwood floors.

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I recently got back from a trip where I was tasked with taking very minimal gear with me because of weight restrictions. I know many of us enjoy having all the options in the world to shoot with but it can be really liberating to take as little as possible and shoot with a minimal setup. While I was packing, I realized that I absolutely didn’t want to leave home without my circular polarizer and in my opinion it’s the most important accessory you will own as a landscape photographer; I would even go as far to say that it’s more important than a secondary lens. As long as you have a camera, lens, and tripod, the next thing in your bag should be a circular polarizer (CPL).

Numerical apertureunit

Just in case you’ve never seen what a CPL can do to fully cut out reflections, above is an example. Both images are untouched and straight from camera. Using a polarizer can completely change your ability to capture photos that you aren't able to do otherwise. This isn't something you can fix in editing or manipulate in Photoshop and should be a prime reason why you always have one with you.

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Haze can absolutely ruin a sunrise you forced yourself out of bed for or that sunset you set up and patiently waited hours to capture. This actually happened to me far more often than I’d like on my recent trip but thankfully I was able to salvage some moments using my CPL.

You absolutely cannot remove reflections in post - only a POL filter can do this. You can darken the sky in post, for sure, but you run the risk of odd haloing effects at edges if you overdo it.

One of the best ways to utilize this natural saturation is within a lush forested shot. Shooting at a river or waterfall tends to have a lot of moisture. That moisture builds up on the surrounding plant life creating small reflections on all the foliage in your shot. By being able to cut through those reflections, it produces a saturation you cannot simply add in during an edit.

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The figure above depicts a section of a clad cylindrical fiber showing the core with refractive index of N1 and the clad with index of N2. Also shown is a light ray entering the end of the fiber at angle (A), reflecting from the interface down the fiber. However, if angle A becomes too great, the light will not reflect at the interface, but will leak out the side of the fiber and be lost. This angle, beyond which light cannot be carried in a fiber, is called the CRITICAL ANGLE and may be calculated from the two indices of refraction.

Something not quite as obvious when using a CPL is its ability to create more natural saturation in your images. I say natural saturation because it does more than just add saturation to your image as though you were adjusting a slider in Lightroom.

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Many people believe that using a low N.A. fiber will “focus” the light from a source. This is not true. A narrow N.A. fiber simply admits less light than a wider N.A. fiber, assuming the source is emitting light at a wide N.A..

I think their intention is that it cuts the reflections off the roadway. Granted I think this is all dependent on the road. I'm sure all of us have driven on roads that reflect and don't reflect when it's raining. That said, I have never driven with sunglasses while raining considering it's normally much darker.

Those are excellent points Chris! There is also a lot of dependency on the angle you are shooting relative to where the sun is sometime allowing you to cut out a lot of reflects and other times not as much. I didn't want to get into too much detail as that may have taken a lot more words. Hopefully the pictures speak for themselves!