Sunday, April 18, 2010

Polarizing Filter: The right application and where to use them.

Polarizing filters are among the fewest filters needed in digital photography. The days of lugging around a massive collection of filters to use with the film you are shooting are, well, over. Inside my camera bag I have one filter. A SunPak Polarizing Filter. I have had it since I have had my DSLR. It has been a great addition to my camera bag. I am going to show to examples of what a Polarizing filter is needed and used for.

I have a pair of not-so-expensive pair of sunglasses that I bought last year. I bought them at the mall, thinking they look great, but they wont be that great. I was wrong. They are polarized with a warm tone to them. Yes, I said warm tone. They offer a warmth about them that combined with the polarizing lenses makes viewing everything more beautiful and enjoyable to look at.



I have been thinking about landscapes a lot more lately as the weather is getting nice and the trees are filling in. On my way into my studio last week I finally decided to stop and make a few photographs of this one particular area that I pass quite frequently. I took out my camera and my filter and mounted it to the front of the lens. Now, before I got any further, I must explain that filters can be a little tricky to use. During my search to find the right page to link to that has the filter for sale, I found negative reviews about the product. This particular filter requires a little bit of knowledge before you just go and slap it on and make photographs. The two sets of images below will give a visual to assist in the explanation. A polarizing filter is designed to intensify the blue in the sky and make the photograph pop. It also adds a little bit of contrast to further increase “the pop” that the photo will have. 


Without Filter                       With Filter

DSC_0150  DSC_0147


If you look closely at the image on the left you will see that it is over exposed. You could take the image into photoshop and or lightroom to bring down the exposure and brightness a little bit. However, this is one more step to your work flow that could have been avoided by using the filter. While I was making these photographs, I did not have the intention of writing this article. But, it came to me while I was shooting. So, what I did was take the filter off and made a  photograph. Both sets of images, the top and bottom, all have the same camera settings. The photograph without filter is set to ISO 100  F4.5  1/180 sec. Which is the same for the photograph with the filter If these numbers are alien to you. Let me explain, ISO acts like what film speed used to, allowing the light to pass in fast. F 4.5 is the f-stop the size of the opening of the lens. Rule of thumb I created when I was young, smaller the number the larger the opening, which allows the most light to come in, 1/180 refers to 180th of a second, the time needed to make the exposure. It took 1/180th of a second to expose the photograph.

Basically when you are going to use the filter you have set the camera to give a slight over exposure. As you can see in both sets of images, the scene is over exposed. When you place the filter on the lens it brings down the exposure. Polarizing filters require more exposure in order to function properly. Polarizing filters require a +1 - +2 increase for exposures. (If you notice the image of the filter above, you will see that it is very dark for a filter, in comparison to a UV filter, which is clear and used to protect the front of your lens) This means if the meter in the camera reads the landscape at 1/250 you need to pull it down to around 1/180 with the filter.  One thing that I did see while reading the very harsh reviews of the filter was that it was hard to focus the lens in. If this is the case, simply set the camera to manual focus. 90% of my images are made using manual focus. This allows me to set the focus to get the sharpest image possible. I have noticed with some lenses, using it on auto focus can leave the image with a slight blur. Regardless, if you do experience a blur, just make sure you set the camera or lens to manual focus.


Without Filter                                           With Filter    

 DSC_0149  DSC_0148


Landscape photography is basically the only application in terms of using a polarizing filter. Think water and sky when you think you need to use a polarizing filter. You wouldn’t want to be using one for shooting portraits. Using a polarizing filter will cut down on the editing and post-processing you will need to do to your photographs. The image with the filter has a slight vignette to it and that is it. Everything else was made in camera. If you decide to search for other reviews of the lens, make sure they discuss how to use it before the make accusations about the quality or worthiness of the product. The review that I read makes no warrant as how the product functions or the application (landscape) in which needed. It is a review written without idea as to how it works, functions, or when a polarizing filter is needed. Filters are sold based on peoples ability to use them. Though the Sunpak is a cheaper more economical purchase, it functions just as good as the pricier ones. And the examples above show for this. 

Wikipedia and Filters


Hoya Filters are arguably the best to use. They are more pricier.


Below are three examples of HDR images that I used a Polarizing Filter on to increase the dynamics even further.


      4 1 2


Joey B said...

Thanks... I'm tired of getting these blown out skies up here. I'll try a filter.

Shooting in Florida, the sky always seemed more blue and I never had the problem, but there's something about this latitude and the haze in the Valley that screws me up.

Jeffrey Byrnes said...

Youre welcome Joey.

Well as you can see in the examples. The filter does work and allow for the sky to become present while retaining the foreground.

Let me know how it works for you.

Tony said...

Just took some pics down by the Connecticut river in Springfield during a walk today and was struggling with blown out skies the whole time. I had a polorizing filter in my bag, but it's been so long since I've used it I forgot all about it. Duh, it would have done the trick, and i could have used it to get some transparent river shots too...

Jeffrey Byrnes said...

See, like some people, you are aware of the use and need for the filter. Which had it been used would have given the desired image you were seeking. Im glad to have helped remind you it was in your bag.

Anonymous said...

I was playing around the other day with mine for just a few practice shots, and the difference was obvious and much better...For interior shots in lower light, I'd imagine it would just be in the way, but anything with sky and color? Definitely...! Great post!

Jeffrey Byrnes said...

Thank you for the comment. Low light settings could make for a challenge. I have never tried using one on an interior photograph. I guess, if there was a vibrant color within the space that you would like to amplify or if there is a combination of sky and interior in the composition it may work. But being inside in tungsten or florescent lighting it would be harmful and an inconvenience to use. You would need to increase the exposure time or ISO to allow for more light to pass through the filter. Increasing the ISO could cause noise in the image. And if no tripod is present blur could be introduce from a longer exposure time, based on how little light is available.

Thank you for your feed back!