Why You Need Polarizing Filters
There it is again. The highlight clipping warning on your histogram is blinking.
No matter what you do, you just can’t seem to get rid of it!
It's particulary bad when you’re out on a bright sunny day by the water. The glare makes it just about impossible to get your autofocus to work.
It's just as frustrating when you try to photograph stunning architecture but the glare causes your camera have a melt down metering the light.
And when you get home from a day shooting outdoors, you’re disappointed because the sky is blown out in nearly every one of your photos. So bad that there’s no hope to recover it in post.
But there is good news. There is an inexpensive piece of gear that could be a total game changer for you.
Are you ready for truer, richer colors in your outdoor photos without blown out highlights?
Then say hello to the polarizing filter.
Sunglasses for Your Camera?
There is a good chance that you own a set of polarizing sunglasses. These help your eyes cope with glare when you’re driving or playing outdoor sports like skiing or tennis.
A polarizing filter is a lot like putting sunglasses on your lens – it helps eliminate the glare that makes it hard to focus and blows out your highlights.
But that's not the only benefits of a polarizing filter.
Not only will your colors look richer and truer with a polarizing lens, it even helps you see beneath the surface of water!
Before Filter After Filter
Let’s look at what polarization is so you understand how adding a polarizing filter improves your photos.
What is Polarized Light?
This is a hugely simplified explanation of what polarized and unpolarized light is.
A physicist could explain it better, but be gentle on me – I'm just a photographer!
So here goes:
The light that reaches our eyes from the sun and artificial light sources contains electrical fields that move in different directions at the same time – up and down and side-to-side.
When these waves hit a smooth flat surface, they scatter in all different directions, causing glare.
So passing light through a polarizing filter makes the scattered light move in a single direction parallel to the object, which eliminates the glare.
Now let's look at when you should add a polarizing filter to your lens.
When Should You Use a Polarizing Filter?
You should add a polarizing filter to your lens anytime you’re out shooting in bright daylight, or around reflective surfaces like water or glass (or even sweaty skin!)
By cutting out the glare, a polarizing filter gives you truer colors and also increases contrast, to make your subject ‘pop! in your frame.
In particular, polarizing filters really help create darker and more dramatic skies when you’re shooting landscapes, and at the same time, controls your highlights so you don't blow out all the detail.
They work best when you’re turned 90 degrees from the sun. Polarizers won’t help at all if you’re shooting right into the sun because the light is just too overpowering.
Polarizing filters just aren't designed to block out 100% of light rays – just to reduce them.
Now, I've made out polarizing filters to be the best thing since sliced bread in this post.
But there are times when it's better to skip them!
When You Shouldn’t Use a Polarizing Filter
While landscape photographers benefit from a polarizing filter nearly all the time, you’re better off taking them off in low-light conditions because they reduce your exposure.
Because the polarizer reduces the light coming into your sensor by 1.5 – 2.5 stops, keeping it on in low-light doesn’t make sense.
So when the sun goes down, take your polarizing filter off your lens!
If, for some artistic reason, you want a shiny reflective look in your photos that’s another time you should remove your polarizing filter.
Want to capture a rainbow? Then take off your polarizer because a rainbow is reflected light – and the purpose of a polarizer is to neutralize reflected light!
So take off that polarizer if you don’t want that beautiful rainbow to disappear into thin air.
Next, let's look at some sample photos taken with and without polarizing filters so you can see the difference for yourself.
Sample Photo with and without Polarizing Filter
You can really see a massive difference in the depth of color in the sky and grass in the photo below.
It almost looks Photoshopped, but it's all due to the magic of the polarizer.
Watch Your Exposure When You Use a Polarizing Filter
One thing to think about whenever you add a polarizing filter is that it reduces exposure by 1.5-2.5 times.
So that mean that you have to compensate by increasing shutter speed, ISO or shooting at a wider aperture to let in more light.
Notice in the photos below that the ISO doubled after adding the filter.
Before Polarizing Filter
Shutter Speed: 1/60
After Polarizing Filter
Shutter Speed: 1/60
The purple hue in the flowers is definitely deeper and more vibrant after applying the polarizing filter.
Now that you've seen a few examples, here's what you need to know before you purchase a polarizing filter.
Purchasing A Polarizing Filter
One of the most important things to know before you purchase a polarizing filter is the diameter of your lens.
Common lens sizes for DSLR cameras are 49mm, 52mm, 58mm, 62mm, 72mm, and 77mm. (Note: this number isn’t a reference to focal length.)
Nearly all lenses already have this information printed on them, but you may not know what you’re looking at.
Manufacturers use the geometric symbol “⌀” to denote diameter. So when you see that symbol followed by a number, you’ll know what size of filter you need to order.
The image below shows where to find the diameter on a Nikkor 35mm f1.8 lens (you'll see diameter markings like this on your own lens.)
As you can also see in the image above, I have a 52mm CPL on my lens, which is the abbreviation for a circular polarizing filter.
What to Do if You Can't Find the Diameter of Your Lens
If for some reason you don’t have the lens diameter indicated on your lens, you can always break out a metric ruler in millimeters.
Measure the distance of the widest part of the lens from the inside rim of the threaded area to the inside rim on the other side of the lens.
Certain types of lenses, like very curved fisheyes that do not have filter threads, or telephotos with a very large front element aren’t suitable for polarizing filters.
In this case, you can check into Cokin filters, which attach to your lens with a holder that’s sold separately from the filter itself.
Want to Learn More About Specific Types of Filters?
I hope that you enjoyed this post about polarzing filters, but they aren't the only type of filter available to enhance your photos.
Our friends at B & Photo have created an extensive article about various types of filters including polarizing, UV, and Neutral Density filters.
They know even more than I do about the construction, types and different brands of filters available.
So if you'd like to learn more on the topic, be sure to check out their super helpful article “A Guide to Filters for Lenses” to learn more on the topic.
If you'd like to make an immediate improvement in your landscapes, make sure that you check out the FREE landscape training below!
Join me for “The 3 Secrets to Amazing Landscapes”
Join me for a FREE landscape photography trainings session! I'll reveal my best secrets for creating landscapes with impact that win you ‘double-tap love' on Facebook and Instagram.
To register, simply click on the ‘Sign Me Up!' button below the image.