Subtle, But Significant: A Polarizer Filter Isn’t Just For Sunny, Blue-Sky Days

Cumulus clouds over Dickenson Bay St. John's, Antigua West Indies.

Cumulus clouds over Dickenson Bay, St. John’s, Antigua, West Indies.

Story & photos by F. M. Kearney

I’m a late-comer. I didn’t make the switch to digital until 2014. As a film shooter, I relied heavily on filters. Everything from warming to ND grads to a vast array of special effect filters were permanent residents in my camera bag. Nowadays, digital imaging can replicate many of those filter effects – often much easier and with far more control. But, as good as digital technology is, it still can’t duplicate the effects of a polarizer filter. The photo above is a classic beach scene where a polarizer works most of its magic. By filtering out the glare and atmospheric haze, the true color of the sky comes forth revealing puffy, white cumulus clouds as far as the eye can see.

Most photographers are well aware of the benefits of using a polarizer in conditions such as this. The effects are obvious and quite striking. What might not be that obvious are its effects on a cloudy day. Overcast skies are the generally preferred conditions for shooting flowers. At this time of year, there’s certainly no shortage of subject matter. All of the following images were shot on the same cloudy day in the rose garden of the New York Botanical Garden.

Shrub rose buds (Rosa) "Marc Chagall" New York Botanical Garden Bronx, NY. Polarized shot on right.

Shrub rose buds (Rosa) “Marc Chagall” New York Botanical Garden, Bronx, NY. Polarized shot on right.

 

Shrub rose and bud (Rosa) "Marc Chagall", New York Botanical Garden, Bronx, NY. Polarized shot on right.

Shrub rose and bud (Rosa) “Marc Chagall”, New York Botanical Garden, Bronx, NY. Polarized shot on right.

In each of the examples above, the polarizer removed the glare from the petals of the shrub roses – restoring their rich, green color. It’s a subtle difference, but it does make a substantial improvement in the photos. Sometimes, however, the effects are barely noticable, as in the example of the floribunda rose below.

Floribunda rose petals (Rosa) "Garden Delight," New York Botanical Garden, Bronx, NY. Polarized shot on right.

Floribunda rose petals (Rosa) “Garden Delight,” New York Botanical Garden, Bronx, NY. Polarized shot on right.

You really have to study the photo to see just what the polarizer is affecting. If you look above the large rose and to the bottom-left of the blurry bud, you will see that a small amount of glare has been removed from a tiny patch of green foliage. Without a doubt, this is a borderline case. For all intents and purposes, I probably wouldn’t even use the filter if its effects are this minimal. I did so in this case for the purpose of this article.

Unless the foliage has been wet by rain, or covered with early-morning dew, the effects of a polarizer in overcast conditions can be hard to detect. Before going to the trouble of attaching it to my lens, I like to hold it up to my eye and rotate it to see if anything is being affected. Some photographers might be tempted to leave it on the lens for the duration of the shoot, whether it’s needed or not. That really isn’t the best practice because the filter will just serve as an additional (and unnecessary) surface to attract dust and glare – not to mention causing a couple of stops reduction in light. I was using a 70-200mm lens with two extension tubes – not only magnifying the image, but also the slightest movements. Even though the winds were calm, the flowers still weren’t completely stationary. In situations like this, I try to keep my shutter speed above 1/60 second. Raising the ISO is always an option, but I prefer to keep it as close as possible to 100 to avoid having to deal with increased noise. Therefore, I only use a polarizer when it’s absolutely necessary. Of all the photos I shot that day, it had at least some effect on about 99% of them.

The flat-lighting on overcast days is great for photography. But, all flat-lighting isn’t created equal. It may not be (pardon the pun) glaringly obvious, but glare is almost always present in varying degrees. The lack of a polarizer certainly won’t ruin the shot, but the side-by-side comparisons clearly show the benefits of using one as opposed to not.

NOTE: The filter was actually attached to the lens for the “without polarizer” shots, but rotated to its weakest setting.

F. M. Kearney began his photography career as a photojournalist for New York City newspapers. His focus soon shifted to capturing the beauty of the natural world. As an award-winning nature photographer, Kearney’s images have been widely published. A slight departure from photography, his recently published horror novel, “They Only Come Out at Night,” about supernatural happenings in the New York City subway (partially inspired by his travels as a photojournalist), is available on Amazon. To see more of Kearney’s work, visit http://www.starlitecollection.com.