The One Filter You Can’t Live Without.

The Weekly Photo Challenge topic is Landscape, so rather than simply share a few landscape photos I’m going to talk about the one filter that should be in every nature and landscape photographers camera bag.

The one filter that cannot be duplicated in the computer, and the one filter I never leave home without.

Straight out of camera, without polarizer.


That filter is the Circular Polarizer.

You can duplicate graduated neutral density filters all day long in Lightroom.

You can even simulate the effect of a straight neutral density filter simply by photographing in lower light, using smaller apertures, or lower ISO settings, thus allowing you to get longer exposure times.

However when it comes to removing the glare on shiny reflective surfaces like wet rocks and leaves, or the reflections on the surface of a flowing stream to reveal the stream bed below, there is only one way to do it. And that is with a good quality Circular Polarizer filter, or CPL for short.

Same scene and camera settings, this time using a polarizer.

What does a Circular Polarizer do?

A circular polarizer is a filter that attaches to the front of your lens, usually by screwing onto the front filter threads. (Now you know why those threads are there 😉 )

What does a CPL do?

Notice how in the first image the colors are much less saturated and the details below the waters surface are much less visible. The is cause by glare. Notice how in the second image, shot using the same exposure settings,* the colors are richer, more saturated, and there is more visible detail under the water.

While a CPL can also help increase contrast and saturation in a photo,  both of these can be duplicated in the computer, glare and reflection removal can’t.

*Note: The second image is darker due to the ability of the Circular Polarizer to reduce the amount of light by as much as 2-stops. This is an added benefit when trying to use longer exposure times to capture flowing water with that silky smooth look.

The Benefits Continue Into The Final Image.

The better the image you get straight out of the camera the better the final image will be after post processing. The following are the above two images, processed as identically as I could. While this is totally subjective on my part the second image, the one where the circular polarizer was used, is the better final image.

Final enhanced image using the RAW file captured without the use of a CPL
Final enhanced image using the RAW file captured using a CPL

Tips On Buying And Using A Circular Polarizer.

1 – Buy the best you can afford. 

Cheap CPL filters can cause image softness as well as impart a color cast on your photo. I’ve used CPLs from B+W, Lee, and Singh Ray with excellent results. Be forewarned, good filters are not inexpensive, though in my opinion you get what you pay for. For more budget friendly CPL filters, check out Tiffen, or Hoya. I have no experience with the latter two, but I have read good things about their line of filters.

2 – Avoid using a CPL when photographing wide scenes.

One thing polarizers do very well is darken blue sky. Too well if you over adjust the filter. BUT, and it’s a big but, the effect of a CPL is greatest at 90° to the light source, for a landscape photographer this is likely the sun. The effect is reduced more and more as the angle to the sun changes. This is a big problem when photographing wide scenic landscapes with a lot of sky. The result will be part of the sky will be noticeably darker when gradually fading across the frame. This is a royal pain in the backside – by that I mean darn near impossible –  to correct in the computer.

3 – Don’t for get to readjust when you recompose.

You can adjust the amount of polarization on the image by rotating the filter. As mentioned above the greatest effect is at 90° to the sun. So once you adjust the amount of polarization you want in an image and then move the camera for another composition, don’t forget to readjust the filter. I find it to be much easier to see the effect in live view rather than looking thru the viewfinder, but that could just be my aging eyes.

4 – You only need one.  

Some of you may be thinking, “I have more than one lens that I use for landscape/waterfalls. Do I need a filter for each lens?” The answer is no.

Buy a filter that will fit the lens you own with the largest diameter filter threads. The buy inexpensive step-down rings to fit the filter to all of your other lenses.


30 thoughts on “And One Filter To Rule Them All

  1. Nice article, Jeff. My B&W lives on my lenses most of the time and I even use it on my macro from time to time to remove glare from leaves, etc. A handy step-down ring means it’s the same filter!

    1. Thanks, Kris. Step-down rings are the greatest. I can’t see the point of owning a different expensive filter for every lens you own. I suppose if you have money to burn, sure, for me I’ll stick with one filter for my largest diameter lens and a bunch of $5 step-down rings.

  2. Very useful tip! I love using the filter since the first time I discovered it but I didn’t realize it was the cause of the darker sky on large landscapes pictures.
    And since I was already thinking of buying another one for mu second lens, I now know I don’t need to! Thanks!

    1. Trust me, I learned about the uneven polarization the hard way. The worst part was I didn’t realize it until I was home and uploading the photos. Oops!

      1. I’ve seen it a few times on some of my pictures but not so often as to realize it was from the filter. still wondered why it happened, though. Going to bed a little more intelligent, thank you 😉

        1. One thing I didn’t mention in the article, if you have a sky filled with dramatic clouds it won’t be nearly as noticeable. It’s when you have a clear blue sky that you’re really going to see it.

            1. And now you know why. Funny thing is, I was just on the website for a new company touting the crystal clear qualities of there filters, including their CPL. I won’t name the company, but in the before and after example images for their CPL there was that very obvious darker blue area in the sky in the “after” image.” I can’t believe nobody on their end has noticed it.

  3. Great post. And shots. I used to use my CPL all the time but I haven’t been carrying it with me lately. You’ve inspired me to dust it off 😊

    1. Yes it is. In fact I had the owner of a car swear up and down i would not be able to capture the very faint airbrushed flames on the front of his drag race car, because nobody else had been able to. I can only assume these people were using point and shoot cameras or not using a CPL because once I set up my shot a quick twist of the filter revealed the flames in all their glory.

  4. I’d like to understand how you used such long exposures with JUST a circular polarizing filter. I have a CPL but it only reduces exposure by ½ a stop of so.

    Buy a filter that will fit the lens you own with the largest diameter filter threads. The buy inexpensive step-down rings to fit the filter to all of your other lenses.

    Are the step-down rings cheaper and easy to remove compared to buying a CPL for each lens (assuming one only has two to three lenses)?

  5. I’d like to understand how you used such long exposures with JUST a circular polarizing filter. I have a CPL but it only reduces exposure by 1.3 stops. That is hardly enough to get 15-20 second exposures to smooth water (unless one is already shooting in a dimly lit scene). Can CPL and ND filters be used together?

    Buy a filter that will fit the lens you own with the largest diameter filter threads. The buy inexpensive step-down rings to fit the filter to all of your other lenses.

    Are the step-down rings cheaper and easy to remove compared to buying a CPL for each lens (assuming one only has two to three lenses)?

    1. These really aren’t that long an exposure. Both of the photos used for this article have exposure times of only 1.6 seconds. They appear to be longer than that because the water was flowing fairly quickly.

      The thing you need to realize is that the blurred look of the water is as much a result of how fast the water is flowing as it is the length of the exposure. The faster the flow the shorter the exposure time required to get the desired effect. Conversely the slower the flow the longer the exposure you would need to achieve the same result. Sometimes I can get that perfect silky appearance in as little as 0.5sec.

      Other things to consider when you need or want longer exposure times are ISO and aperture. Use the lowest ISO, in the case of many Canon cameras that’s 50, and I’ll also stop down to a very small aperture, something like F/22. Of course I also generally prefer to photograph waterfalls on rainy overcast days and/or early or late in the day. All of which means lower light and therefor longer exposures. I’m regularly able to get exposures of up to 20 seconds with just low ISO, small aperture, and low light.

      As for using a CPL with an ND filter, yes you can use them together, I do it all the time. One of my favorite filters is my Singh Ray Vari-N-Duo. It’s a circular polarizer and variable neutral density filter(2-8 stops) all in one.

      Step down rings are dirt cheap. Especially if you buy them on eBay. If I remember correctly I paid less then $5 U.S. for the ones I use. You will spend a little more if you buy the brand name ones from places like B&H, but the import knock offs get the job done. Even the brand named ones are cheaper than having a different filter for each lens, particularly if you’re buying good quality filters.

      1. Thanks for the response and tips. Over the last 10 years, I’ve been scammed too many times on eBay as both a buyer and seller. I no longer shop on eBay.

        My camera and lenses are not water sealed. I shoot in dry weather. I guess I don’t live in areas with raging water flows. I can’t achieve that silky smooth water without 30-60 second exposures and an ND filter. Sometimes I’m forced to shoot at the brighter part of the day due to tome constraints. I invested in a 10 stop ND filter. The CPL doesn’t help with the long exposures but I want to use it to reduce reflections.

        1. The brighter part of the day is really tough when it comes to getting longer exposures, there’s just too much light. This is when you really do need neutral density filters, like a 10-stop.

      2. Ack. I forgot to ask. With the screw type circular polarizer like the one I linked to, how does one use it with an ND filter? Do I set the polarizer first the attach the ND filter? How do I prevent the CPL from moving when I screw in the ND filter?

        1. That’s correct, you’d have to set the polarizer and then add the ND. You’re going to have to hold the CPL to keep it from rotating while screwing on the ND. This is more or less how the Singh Ray filter I mention works. There’s a ring to adjust the polarizer and then an outer ring to dial in the number of stops on the variable ND part of the filter. The CPL part is stiff enough that it does’t move much if at all when setting the ND. Of course the convenience of having both a CPL and Variable ND all in one comes at a price. An almost $400 price!

          One more thing to watch out for when stacking filters is vignetting. If the filters together are thick enough and or the lens is wide angle enough the vignetting could be so much that it will appear like you’re photographing through a tube. You will ned to zoom in a bit to get ride of the vignette.

            1. It’s not the F-stop thats the issue, it’s the focal length. If I use the Vari-N-Duo on my 17-40 lens I have to zoom in to about 30mm. Otherwise it’s like I’m photographing through a long pipe. See the severe darkening in the corners? That’s because the filter protrudes into the field of view when using an ultra wide focal length. This shows the severe vignetting caused by thick or stacked filters on a wide angle lens. This was taken at 25mm on a full frame camera.

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