Filter Guide for Landscape Photography: Polarizers
May 30th, 2012
Here at Sea to Summit Workshops, we often get asked for advice on which filters to purchase…and rightfully so! There are a myriad of photo filters on the market from UVs to Polarizers, NDs (neutral density) and GNDs (graduated neutral density), red filters, blue filters, and even gold-n-blue filters. But for landscape photography, there are two classic choices: the polarizer and (G)NDs. As I have used a variety of filters over the years, I will try my best to write a straight forward filter starter guide for landscape photography. Along the way, I will add some personal insight as to what I use, when, and why.
Part I: Polarizers:
What do they do? Simply put, polarizing filters work by reducing the wavelength of reflected light, and maximum polarization works best at 90 degree angles to the sun with reduced effects as you get closer to zero and 180 degrees. So if you are facing the sun, maximum polarization will be directly to your left and right with minimum polarization happening in front and behind you. Although software exists to mimic the effects of a polarizer, it just isn’t as good as the real thing and probably never will.
What are they good for? Polarizing filters will help reduce reflections and glare on non-metallic surfaces enabling you to 1) see below the surface of (relatively still) water, 2) reduce glare on wet surfaces such as rocks and foliage to increase color saturation, and 3) darken blue skies and add contrast to cloudy skies. In addition, most polarizers block about two stops of light, so if you need to lengthen your shutter speed, adding a polarizer can help. For example, if the light allows for a 1 second exposure, adding a polarizer would allow a 4 second exposure. Along the coast, I personally use a polarizer during brighter daylight hours to get a richer, bluer sky and to reduce the harsh highlights of midday sunshine. But as the light fades, I tend to put my polarizer back in the bag for two reasons. The first reason is all about shutter speed. When working with ocean surf, I use a few select shutter speeds for as long as possible. The darker it gets, the more I have to compromise my depth of field (aperture) and image quality (ISO) to maintain those select shutter speeds. At some point, my personal thresholds will be reached where I don’t want to compromise any further. I can gain back two precious stops of light by putting the polarizer away. The same applies for any photography where shutter speed is critical such as with wind and wildflowers. The second reason is a personal choice on how I want to render reflected light. Mid-day sun on wet surfaces generally looks harsh and uninviting, but during the golden hours of sunset or sunrise, reflections may be a welcome addition to add depth to an image. Wet rocky surfaces shimmer with golden accents and smooth sand can glow with the warm tones of sunrise/set, so why would I want to reduce them with a polarizer?
What are the drawbacks? Ultra-wide focal lengths will suffer from uneven polarization, especially noticeable in clear skies. Keeping in mind the 90 degree rule mentioned above, portions of the sky will become comparatively darker than others. While this does not bother some photographers, I personally find it a visual distraction more often than not. I will still use one if it helps improve the scene in front of me, but I realize some burning and dodging during post processing awaits me back home in order to better balance the uneven tonal values. By nature of their construction, polarizers tend to be thicker than non-rotating filters. As a result, even thin mount polarizers can obstruct your field of view at extremely wide focal lengths. Sharing a personal experience (and one shared by at least one other photographer I know), putting filter holder systems such as the LEE Foundation Kit onto a cheaply constructed polarizer can lead to the polarizer coming apart. Too much weight on the outer threaded glass element can result in it detaching from the threaded ring that mounts to your lens. A quality constructed polarizer will not suffer from this problem nearly as often and will save you the hassle of “buying twice”.
What type of polarizer should I get? There are many types of polarizers on the market. Linear polarizers came first, but with the advent of SLRs and their auto metering and focus systems, circular polarizers (CPLs) came to market as linear models interfered with these new “auto” features. However, within the category of circular polarizers, numerous variations exist. Many companies offer warming polarizers which do exactly what the name suggests and add a warm cast to the image at the time of exposure, but a warmer white balance with digital cameras can simulate this to a degree. Color specific polarizers such as Cokin’s Blue and Yellow and Singh-Ray’s Gold-N-Blue accentuate polarized light in specific spectrums and can lead to some strikingly unique images when used appropriately as well as being almost impossible to duplicate with computer software. I personally have a thin mount Singh-Ray Gold-N-Blue polarizer in my kit (read my blog entry on this filter here). A large variety of color combinations in conjunction with a polarizer are available from at least a few companies including Cokin and Hoya, but you rarely see them being used (and probably for good reason). As well, Singh-Ray makes a line of LB polarizers which stands for “lighter and brighter”. These allow up to 2/3 of a stop more light through compared to most other polarizers The LB Color Combo is a marriage of their color intensifying filter and warming polarizer. Singh-Ray also combines their variable neutral density (Vari-ND) filters with both the LB polarizer (Vari-N-Duo) and LB Color Combo (Vari-N-Trio).
What size should I get? If money is no object, feel free to buy a polarizer for every lens you own. But if you would rather not spend thousands of dollars on polarizers and carry the extra weight, I recommend finding a system which requires the least amount of duplicate investment. This could simply mean buying one polarizer for your largest size lens and getting step-up rings for your smaller lenses. For example, if you own lenses with 77mm, 72mm, 67mm, and 62mm threads, purchase just the 77mm polarizer and get a 72-77mm, 67-77mm, and 62-77mm step-up rings. If you plan on using threaded filters or a filter holding system in front of your polarizer, make sure to get a threaded version. Just be aware that rotating a polarizer with a filter holder for GNDs in front requires a bit more fiddling to get the polarization and the angle of your GNDs straight, but that is exactly what I do. Another option is the large 105mm polarizers which mount onto the front of filter holders like the LEE Foundation Kit. With this type of set-up, the polarizer travels with the filter “kit”. This solution offers better ease of use when using graduated neutral density filters (GNDs) as the polarizer can rotate independently in front of the other filters. Note: As mentioned before, with ultra wide focal lengths, both options described here will show some physical obstruction at the widest focal lengths.
What do they cost? There is an extreme price range for polarizing filters. They can start at $40 for simple circular polarizers (77mm) to $400+ for specialty varieties. 105mm polarizers run from $150 – $600. After having a cheap polarizer repeatedly come apart when using my LEE Foundation holder, I switched to the B+W Kaeseman Multi-Resistant Coating (MRC) for about $150 after reading of its solid brass mount. It can be stiff to rotate at times, but I can honestly say it has only come apart once or twice in the past three years of use. My cheap polarizer would fall apart almost every time out. My next purchase will undoubtedly be a Singh-Ray LB model in a thin mount for the extra light it lets through and for less obstruction with my ultra wide lenses.
- Wikipedia Article on Polarizers
- Luminous Landscape Polarizer Tutorial
- “Nikon Help Hotline” Youtube video
- Camera Labs Youtube video
- LEE Filters Poalrizer video
Questions? Please leave them below and feel free to leave comments about your personal experience with polarizers.