Polarizing filters and their use:
The one thing to learn about polarizing filters is that they were invented to use with photography, so that you would get more accurate and rich colors in your landscape photos.
A polarizing filter is a piece of glass that goes over your camera lens and reduces haze, reflections, and glare. It also darkens blue skies.
Without getting too scientific, light waves that bounces off water, leaves, glass, and other reflective materials become polarized, which means they vibrate in a special way; polarizing filters are designed to block this polarized light from reaching your camera sensor.
Most photographers use circular polarizing filters, which screw onto the lens and can be rotated to amplify or reduce the polarization effect. So by turning a polarizing filter in one direction, the photographer can block out reflections, and by turning the polarizing filter in the other direction, the photographer can ensure the reflections are clearly visible.
This is a perfect example of what a good polarizing filter will do for your photos. As you look at this photo, there are things you can see that you would not normally see without a filter.
1- A polarizing filter accomplished the ability to look into the water. Normally you would get a reflection taking this photo. Reflection gone. It’s the most amazing thing that happens that you will see when you start using polarizing filters.
2- The colors in the photo in general are richer in color. That is because the filter cut the reflections off those items that reflect. The greens are greener, the sky is bluer, and the contrast also is increased, making a good rich color photo.
WHY ARE POLARIZING FILTERS USEFUL?
Polarizing filters are known for three highly visible effects:
- They reduce reflections, so you can photograph through glass and water.
- They reduce glare, so you can capture more saturated colors.
- They cut down on polarized light in the atmosphere, which causes skies to turn a deep, dark blue.
In certain situations, these effects are a big deal. For instance, if you’re photographing a beautiful rocky tidepool, a polarizer can eliminate pesky reflections and reveal the beauty underneath. And if you’re photographing a desert landscape at noon, the polarizer will turn the hazy blue sky into a darker, more evocative color.
In fact, polarizers are used for LANDSCAPE PHOTOGRAPHY all the time, because you’re often faced with reflective water and foliage. Don’t like the reflections in the water? Use a polarizer. Want to capture more saturated fall colors? Use a polarizer.
HOW TO USE A POLARIZING FILTER:
Polarizers are wonderfully easy to use.
First, when you find a scene that requires reflection or glare reduction, simply screw your polarizing filter onto the front of your lens.
Next, look through the camera viewfinder, then slowly rotate the polarizer. As you rotate the glass, watch the areas of your composition with obvious reflective elements.
After a few moments of rotation, you should see the reflections start to fade. Continue to rotate the filter until the reflections have disappeared (or have reached a level that you like).
Then leave your polarizer as it is, and proceed to adjust your other camera settings for the proper DEPTH OF FIELD, exposure, etc. Note that you should always set your exposure after applying the polarizing filter, because a polarizing filter blocks out light, which in turn requires EXPOSURE COMPENSATION.
Another key fact: Polarizing filters don’t always work perfectly. Depending on the angle of the sun and the quality of the light, you may notice significant changes to a polarized image – or you may notice no changes at all.
For the greatest effect, try to keep the sun at a 90-degree angle to your lens. A common trick is to make a finger gun with your thumb and index finger. Then point your thumb at the sun and rotate your index finger in a circle (as if your thumb is the axle and your index finger is the spoke on a bicycle tire). Wherever your index finger points will experience the strongest polarization effect, whereas other areas of the scene will experience the polarization effect to varying degrees.
WHEN TO USE A POLARIZING FILTER:
While you shouldn’t use a polarizer all the time, here are a few situations when it’s a good idea to screw on that filter:
WHEN PHOTOGRAPHING WATER:
When photographing a scene with water, you’ll often get unwanted reflections, and a polarizer can make all the difference.
For example, when I was snorkelling off the coast of Indonesia a few years back, I took a series of photos without my polarizer. The water looked murky, plus it had a big, unpleasant reflection on the surface.
But when I used my polarizing filter, everything changed; the water become a crystal-clear, bright-blue color, and the shots had far more impact.
Of course, you shouldn’t always apply a polarizing filter to water shots. Sometimes, you’ll want to maintain reflections in a scene – think of a mountain reflecting in a quiet lake – in which case you should leave the polarizer in your bag.
But more often than not, if water is featured in your scene, a polarizer is a good idea.
TAKING A PHOTO WITH A BLUE SKY:
The color of the sky can change dramatically with a quick twist of the polarizing filter. A pale blue can turn to a vibrant, deep blue color, though the extent of the effect does depend on the sun’s position.
(Also, a polarizer can cut out a lot of the smoggy haze that you’ll find in city scenes.)
When you’re photographing a landscape on a clear day, it’s often a good idea to at least try using a polarizer, especially if you’re shooting when the sun is high in the sky. The effect is quite striking, and it can even be the difference between a mediocre shot and a great shot.
TREES AND LEAVES:
When you think of reflective objects, “leaves” probably isn’t the first item that comes to mind.
Yet leaves are actually quite reflective, and this reflectivity can seriously reduce color saturation.
A circular polarizer is particularly useful when capturing fall colors – professional photographers use polarizers pretty much non-stop when photographing the autumn landscape – because it cuts down on reflectivity and glare, which consequently increases color intensity.
When photographing reflective glass
If you like to photograph buildings or cars, a polarizer can be a big help, assuming you want to emphasize the building/car interior.
Glass is pretty reflective, but a polarizer can do a very nice job of removing those reflections.
HOW TO CHOOSE A POLARIZING FILTER:
Most lenses take screw-in filters that attach to the end of the lens barrel, just over the front element.
Because different lenses feature different diameters, you’ll need to take note of the diameter on your specific lens, then buy a polarizing filter with a matching size.
If you have several leness with different diameters, you’ll need to buy several polarizing filters (annoying, I know; the alternative is purchasing step-down filters, but they can be cumbersome and frustrating to work with).
Keep in mind that good polarizers are not cheap – but as I emphasized above, you shouldn’t skimp and buy a poor-quality filter for your top-notch lenses. Instead, pay for a good polarizer made by a reputable brand (Hoya and B+W are two good places to start!).
HERE IS SOME GREAT LINKS TO LEARN MORE ABOUT POLARIZING FILTERS: