I’m a big fan of the polarizer, so much so that each of my lenses wears a polarizer that never comes off in daylight. A couple of years ago “Outdoor Photographer” magazine published my article on using a polarizer, a slightly modified version of a blog post that appears in the Photo Tips section of this blog.
If you read that article, or pay much attention to what I write here, you know that while a polarizer can really crank up the blue in your sky, I’m not generally a fan of what the polarizer does to the sky. I find blue sky boring—making it more blue just distracts from my primary subject. And worse still, because polarization varies with the angle of view (maximum polarization occurs when composing perpendicular to the sunlight’s direction, minimum when you’re parallel to the sunlight), wide shots (in particular) display “differential polarization” that manifests as unnatural sky-color variation across the frame.
Where I find a polarizer most indispensable is terrestrial reflections. With a simple twist of a polarizer, a mirror reflection on still water is magically erased to reveal submerged rocks and leaves. More than the reflections we see on still water, a properly oriented polarizer removes distracting, color-robbing glare that jumps off of rocks and foliage. And you don’t need direct sunlight to enjoy a polarizer’s benefits—because reflections and glare exist in overcast and full shade conditions, a polarizer can significantly enhance those images as well.
But back to this differential polarization thing. As most know, a polarizer isn’t a filter that you simply slap on a lens and forget about. A rotates in its frame, changing the amount of polarization on the way—if you’re not orienting (rotating) your polarizer with each composition, you’re better off keeping it in your bag. Watching through your viewfinder as you rotate, you’ll see the scene darken and brighten—maximum polarization occurs when the scene is darkest. These changes may appear subtle at first, and in some cases will be barely visible, but the more you train your eye, the easier it becomes to detect even the most subtle polarization.
Since polarization varies with the angle of view, and any image encompasses a broad angle of view, the amount of polarization you see in any given image varies. While differential polarization is a real pain in images with a uniform surface (like a blue sky), understanding that a polarizer isn’t an all or nothing tool allows you to dial the reflection up in some parts of the scene, and down in others. Rather than automatically dialing the polarizer until the scene darkens (maximum polarization), or until the reflection pops out (minimum polarization), turn the polarizer slowly and watch the reflection advance and retreat as you turn.
That’s exactly what I did with the above image from last week’s Yosemite trip. The sunlit vestiges of a day-long rain swirled above Valley View and reflected in the drought-starved Merced River (one storm does not a drought break). Here I opted for a wide, vertical composition that left room for both foreground and sky tightly framed by El Capitan on the left and Cathedral Rocks and Bridalveil Fall on the right.
Faced with a crisp reflection and a submerged jigsaw of river-worn granite, I refused to choose one or the other. Instead, I composed my scene with a group of exposed rocks to anchor my immediate foreground, then carefully dialed away enough reflection to reveal the rounded rocks, while saving the portion of the reflection that duplicated the Yosemite icons.
I use Singh-Ray filters (polarizers and graduated neutral density)
Click an image for a closer look, and to enjoy the slide show