Camera Talk: Using Polarizer Filters

Composite comparison of polarized and un-polarized images of Mount Hood

Composite comparison of polarized and un-polarized images of Mount Hood

This is the first in a pair of articles on using a polarizer filter to greatly improve your photographs. It’s something that almost any weekend photographer (like me) can do easily and inexpensively. Polarizer filters are especially important for photographs of mountains, waterfalls and flora. In other words, the very things that we seek out when exploring Mount Hood and the Gorge!

The concept of a polarizer filter is straightforward: it consists of a pair of glass filters that rotate for optimal effect. The purpose of a polarizer is to screen out glare from reflective surfaces — rocks, water, leaves, clouds — allowing the true colors of your subject to pass through to your camera’s sensor (or film).

With a digital SLR, you can fine-tune the degree of filtering with great subtlety, but even with an electronic viewfinder you can still see the effects with many point-and-shoot cameras. Cameras with a threaded filter mount are ideal for using a polarizer filter. Though a bit more awkward to manage, you can even get decent results by simply holding a filter in front of the lens on a camera without filter threads!

Circular polarizer filter

Circular polarizer filter

For digital cameras, you need a circular polarizer (and almost all polarizer filters are now of this type). These include a second stage of filtering designed for digital sensors. You also need to know the filter mount size of your camera threads — printed on the lens with a digital SLR and in the specs or on the camera body for other digital cameras that include threads for attaching a filter.

A consumer-grade polarizer will set you back $30 to $50, with the price proportional to diameter of the filter. You can buy these filters at any camera store, and excellent brands like Tiffen and Hoya are both affordable and widely available in stores and online.

When should you use your polarizer?

Professionals frown on leaving a polarizer on your camera unless you’re using it for a specific shot, as these filters reduce the amount of light available to the camera — and in theory, more glass in front of your lens impacts the quality of your images. This makes sense… if you’re a professional.

But for weekend photographers (like me), it’s just easier to leave them on when you’re using your camera in the outdoors. This is because most polarizer filters (like the one pictured above) double as UV filters, meaning that you can use a polarizer in place of the UV filter that is standard protection for a digital SLR lens. But if you’re shooting in low light, it’s probably a good idea to switch to a UV filter, especially if you’re taking hand-held shots. Simply carry both with your camera if you do need to switch.

Too many stacked filters left vignetting in the corners of this image of Newton Creek and Mount Hood

Too many stacked filters left vignetting in the corners of this image of Newton Creek and Mount Hood

You can also attach a polarizer to the outside of your UV filter, “stacking” them. This is convenient, but has tradeoffs. First, three layers of glass in front of your lens could affect your image quality, or even the ability of your camera to auto-focus. Second, the thickness of stacked filters can create a “vignette” effect on your images (see example, above), where the edge of the filters encroaches on the corners of your image. So, it’s usually best to just use one filter at a time, and thus my habit of keeping the polarizer on whenever I’m shooting outdoors.

The following are some tips for using a polarizer in the three most useful situations: mountains, waterfalls (and streams) and flora. Try it, and you will be amazed at your results from this simple piece of equipment!

Mountain Photography

Mountain photography usually involves capturing wildly divergent colors and contrasts. A typical summer scene on Mount Hood might range from bright white snow to nearly black shadows, with a rainbow of colors between. Add reflective glare and atmospheric haze, and what might seem like stunning images out on the trail too often results in disappointment when you get home to discover the muddy, washed-out images that your camera captured.

A polarizer filter does a terrific job of remedying these challenges. Simply attach the filter to your lens or camera, and adjust by turning the outer ring while watching through your viewfinder (or on your monitor). You’ll be amazed at the vibrant colors hiding behind the glare and haze!

While a polarizer can do great things for color, keep an eye on the sky as you adjust your polarizer setting. A polarizer filter has its maximum effect when the sun is at 90 degrees to the scene being captured — in other words, when the sun is directly to your left or right as you shoot. This can result in a unnatural banding of the sky, with an intensely saturated band running vertically at that 90 degree point (see example, below).

This image of Mount Hood from Elk Cove is a typical example of over-polarizing an early evening image

This image of Mount Hood from Elk Cove is a typical example of over-polarizing an early evening image

Over-polarizing the sky is generally a problem when the sun is at a low angle early or late in the day. Unfortunately, this also happens to be the sweet spot for landscape photography, when softer colors and long shadows combine to make for the most dramatic photo. What to do?

The best plan is to compensate for this banding effect by simply dialing back the filter to a point where you’re still getting improved colors, but without overly distorting the sky color. It’s a tradeoff, but worth doing in the field, as correcting an image with over-polarized sky is tricky using a photo editor. In the end, you’ll still have much better colors using the polarizer, even if not to its full effect.

Some before and after comparisons…

Here are some paired mountain scenes, taken with and without the aid of a polarizer filter. The results speak for themselves: better contrast, more intensely blue skies, better mountain colors and more saturated flora and forests. The only difference in these paired images is the polarizer setting!

First up, Mount Hood and the Muddy Fork valley from Bald Mountain. Note the improved color saturation throughout:



Next, the upper Hood River Valley from Middle Mountain. Notice the improved detail on the flanks of the mountain, where glare hides both colors and contrast on the unfiltered image:



And finally, the White River Canyon. Notice how much more vibrant the Lupine in the foreground are, and how well the clouds are defined in the polarized image:



Waterfall Photography

Where mountain photography is usually best when the sun is shining, waterfall photography is just the opposite. Overcast conditions reduce the amount of glare, and the darker conditions help avoid “blowing out” the bright whites of falling water in your photos. This is especially true when taking a long exposure for that professional-looking, streaked effect.

Yet, even in overcast conditions, the amount of glare reflected off leaves, rocks and water is substantial, and can greatly affect your waterfall photographs. Correcting for glare is easy with your polarizer: simply rotate the ring until reflections from these surfaces fade away. The degree to which you filter out glare is a matter of personal taste, but using your polarizer at the highest setting will produce an amazingly vibrant, striking image.

This 1/2 second exposure of Punch Bowl Falls on Eagle Creek was captured with only a polarizer

This 1/2 second exposure of Punch Bowl Falls on Eagle Creek was captured with only a polarizer

Polarizer filters have a dual benefit for waterfall photography, because they also reduce the total amount of light reaching your camera sensor. Normally, this is a minus for photographers, but when you’re taking long waterfall exposures (usually from 1/2 to 1/8 second), a polarizer can take the place of additional light-reducing filters needed to shoot that slowly in daylight. While

Though I carry the additional light-reducing filters, I rarely need them for waterfall photography, as a polarizer filter is generally enough for exposures up to 1/2 second. For most digital SLRs and point-and-shoot cameras a circular polarizer (coupled with a tripod to keep your camera steady) is more than enough to allow you to shoot really professional waterfall images!

Before and after waterfall comparisons…

Here are a couple of paired waterfall images, each scene shot with and without a polarizer filter. Like the mountain scenes, the only difference is the use of a polarizer.

First, Upper McCord Creek Falls in the Columbia Gorge. Notice the difference in reflection from leaves in the foreground and background:



Next, Metlako Falls on Eagle Creek in the Columbia Gorge. Notice the difference in reflection and color saturation on the maple leaves at the left side of the image:



Photographing Flora

If you enjoy photographing flora, a polarizer is a great way to reduce glare and improve color saturation — especially in wet weather, when leaves are shiny and reflective with moisture. Often, using a polarizer filter to shoot flora means using a tripod, as close-up scenes often mean dark backgrounds.

The good news is that you’ll get a much better picture with a tripod! You’ll be able to compose and focus it more carefully, and use a much lower shutter speed than you could otherwise shoot, allowing for an even more sharp, saturated image.

A polarizer allows the droplets of rain to stand out on this very wet bramble leaf, not the reflection of the sky

A polarizer allows the droplets of rain to stand out on this very wet bramble leaf, not the reflection of the sky

The trick is to balance shutter speed with wind conditions. In perfectly still conditions, you can reliable shoot for up to 1/4 second without having a blurred subject from wind movement, but in somewhat breezy conditions, you’ll have to adjust to at least 1/60th of a second or faster to ensure that your subject isn’t visibly moving in the exposure.

Before and after flora comparisons…

Here are a couple of paired images that show how a polarizer can improve your flora photography. The first is a dry lady fern frond that still has a surprising amount of reflection (the difference in background focus resulted from the auto-focus responding differently to the polarizer settings):



A more dramatic difference is clear in this pair of images showing the glossy leaves of deer fern with and without a polarizer:



When shooting foliage or flora, your best bet is to choose a day with heavy overcast. A general rule of thumb is that if you can see even the most vague shadow of yourself on an overcast day, you’re going to be dealing with glare on foliage that a polarizer cannot fully compensate for.

The following pair of images taken along Eagle Creek in the Columbia Gorge shows the same scene under heavy overcast (May 29) and two weeks later, under bright overcast (June 29):



As you can see, the colors in the first image are much more saturated with a lot less glare, You can see the difference in the foliage in the background, in particular. Both images were shot at the maximum polarizer setting and with the same shutter speed.

Hopefully, these before-and-after images have encouraged you to investigate a polarizer for your camera — or giving another try to one that you already have. You will be glad you did, especially if you’ve though about experimenting with a tripod and slow shutter speed photography. Your photos will dramatically improve, and your main dilemma will be where to hang all those great new images you’re going to want to frame!

Next up: a companion to this article will build on the use of polarizer filters in slow shutter speed photography, featuring a virtual field trip to iconic Punch Bowl Falls on Eagle Creek, and tips on getting that perfect photograph!

Mount Hood National Park on Hike Yeah

Yesterday, I had the great pleasure of meeting Alex Head, host of the weekly Hike Yeah program. We recorded a two-part podcast that covers all aspect of the Mount Hood National Park Campaign, and you can stream or download the first 30-minute segment (Podcast 40) from the Hike Yeah website now:

Hike Yeah | Podcast 40 | Mount Hood National Park Campaign

The second segment will air next Friday at 2 PM, and will appear as Podcast 41 on the Hike Yeah website. Alex is a fine interviewer, and had really done his research into the MHNP project before the show, so we were able to jump right in to the questions that people are most curious about: how would National Park management differ from the Forest Service? Would there be additional entry fees? What about my dog..?? Those questions, and many more are covered in the interview.

The second segment airing next week is a bit more expansive, as Alex focused more on things that I’m doing outside the MHNP Campaign, but I did manage to bring it back to the cause I care about most! Alex provides a terrific service with this program, so if you’re a hiker be sure to subscribe and catch his show every week.

Edited to add in the link to the second part – rambles onto other subjects like waterfall hunts, restoring old trails and the birth of Trailkeepers of Oregon, but does get back to the main theme of Mount Hood National Park toward the end:

Hike Yeah | Podcast 41 | Mount Hood National Park Campaign

Thanks for the opportunity, Alex – it was fun!

Proposal: South Fork Water Works Trail

Lower falls on the South Fork Clackamas River in 1963

In 1913, the young cities of Oregon City and West Linn suffered a serious outbreak of typhoid from an increasingly polluted Willamette River, their sole source of water at the time. The incident spurred Oregon City’s leaders to appoint a “Pure Mountain Water League” and directed it to locate a safer source of drinking water.

The League settled on the pristine South Fork of the Clackamas River in the Cascade foothills. The City of West Linn signed on with Oregon City, offering to pay for one third of the cost of a new pipeline to bring the South Fork water to the two cities. A South Fork Water Board was created to carry out this ambitious project.

By the fall of 1915, the new water district had managed to lay twenty-six miles of 18” pipe from a site at the confluence of Memaloose Creek and the South Fork Clackamas all the way to Oregon City and West Linn. The new pipeline began to carry municipal water on October 7, 1915.

Main falls on the South Fork Clackamas River in 1963

In 1939 the South Fork Water Board expanded the system with the help of one of Franklin Roosevelt’s New Deal recovery programs, the Works Project Administration. This project extended a 24” pipeline upstream from the Memaloose Creek intake to a point upstream, above the 120-foot main falls on the South Fork. This project involved carving a series of three dramatic tunnels and a cantilevered pipeline through solid basalt cliffs.

The new intake improved water pressure downstream, and this system continued to serve as the water supply for the two cities until a new filtration plant was constructed on the lower Clackamas River, in 1958. Both systems were used until 1985, when the South Fork pipeline was decommissioned. Since then, the network of roads, tunnels, plank walkways, log bridges and old pipeline has slowly been fading into the green rainforest of the South Fork canyon.

The story might have ended there, except for the series of spectacular series of waterfalls along the South Fork and Memaloose Creek. By the late 1990s, some of the region’s more adventurous kayakers had scouted both streams, and in the early 2000s, had documented the first known descent of the South Fork by kayak.

Main falls on the South Fork with hiker in 1923

These intrepid kayakers portaged the big waterfalls on the South Fork by following the abandoned tunnels and log bridges left behind by the South Fork Water Board. In doing so, they brought renewed interest to the area, as word of a high concentration of waterfalls spread to other adventurers.

In total, there are five major waterfalls along the final two miles of the South Fork, and two along the last mile of Memaloose Creek, where it flows into the South Fork. The old water works roads and tunnels reach two of the South Fork waterfalls, including the main 120-foot falls, as well as the main falls on Memaloose Creek. The remaining waterfalls are remote, and not reached by the water works roads.

The tunnels and roads along this system are entirely intact and walkable – as several explorers have now documented. A timber bridge over the South Fork at Memaloose Creek is also intact, and is now used by waterfall explorers to cross the stream. These old roads and tunnels offer a unique opportunity for a new trail system that could build on the existing network, and offer an unparalleled blend of natural spectacle, historical artifacts and lots of insight into the history of the South Fork water works project, itself.

(Click here for a larger map)

What would this trail look like? The accompanying maps (above and below) show the sections that would follow old water works grades in yellow. All of these roads have been recently scouted, and are in good shape, and thus easily converted to trails. The six tunnels along the way (one along Memaloose Creek and five along the South Fork) are also in good shape, and easily walked, although at two are long enough that a headlamp is required.

New trails would also be needed to complete the system, and are shown in red on the accompanying maps. A new trailhead and access trail would located on the east side of the Memaloose Bridge, following the Clackamas River downstream, then turning up the South Fork canyon and joining the converted water works grade at the lower South Fork falls (this section along the Clackamas would also serve as an extension of the Clackamas River Trail, extending east to Fish Creek, and the current trail terminus).

Two trail extensions would carry hikers deeper into the canyons of the South Fork Clackamas and Memaloose Creek, beyond the water works roads. A new Memaloose trail would climb a half-mile to a second falls, upstream from the main Memaloose falls. An extended South Fork trail would continue from the final waterworks tunnel, and travel 1.5 miles upstream along the west bank of the river, passing three remote waterfalls before ending at the existing Hillockburn Trail (shown in green on the maps).

(Click here for a larger map)

Look closely at the maps, and you will also see a proposal to add a trailhead at Big Cliff, along the Clackamas Highway, with a footbridge connecting across the Clackamas River to the new South Fork trail network. The concept here is to provide a family-oriented day-use area on this scenic bend in the river that serves as the long-term gateway to the South Fork canyon. Today, this spot is an eyesore – a huge dirt and gravel expanse that suffers from dumping, shooting and other unlawful behavior. The trailhead and day-use concept would turn this blank expanse into a place for families to explore the river and nearby trails, less than an hour Portland.

Future trailhead and day-use area at Big Cliff?

In deep, rocky canyons like the lower South Fork, building new trails is complex, costly and at odds with modern conservation ethics, where blasting a trail through cliffs is no longer an accepted practice. Thus, the ability to convert the water works roads would bring hikers into a landscape that probably would never be reached with modern trails. In many ways, the canyon is an accidental version of the venerable Eagle Creek Trail, in the Columbia Gorge, where the route is famously carved into the cliffs.

The logistics for this proposal are also fortuitous. The water works area of the lower South Fork canyon was specifically excluded from the 2009 Lewis & Clark wilderness act that set aside the upstream portions of the South Fork canyon as new wilderness. This means that while the upper canyon trail must be built with wilderness restrictions in mind, converting the roads, repairing bridges and preserving the historical artifacts in the lower canyon won’t be encumbered by wilderness restrictions.

This is a project whose time has come – in part, because the word is out about the scenic wonders of this beautiful canyon, but also because the historic features ought to be preserved before they are lost to time and the elements.