A circular polarizer is a filter that is really worth having because it’s great for reducing glare from reflective surfaces. It draws the glare from wet leaves or the surface of a pond and allows you to see more detail and color. It also helps cut through haze to enhance the blue in the sky.
But there are times when it is best to remove the circular polarizer before taking a shot. One of these times is demonstrated by Jay while shooting sea anemones under water at Olympic National Park.
In this case the decision whether or not to use a circular polarizer filter sometimes comes down to its one main side effect: light fall out. When you mount a circular polarizer filter on your camera lens, the amount of light reaching your camera decreases by 1-2 F-stops. In other words, a circular polarizer acts as an ND filter no matter how you rotate its front element.
Here is a photo that Jay took with a circular polarizer in Olympic National Park. There was enough light to get away with using a circular polarizer in this photo because I took this photo at midday.
Here is another shot of a sea anemone taken at Olympic National Park. This particular image was taken late in the day under a thin layer of clouds. I did not have enough light to use a circular polarizer; when I tried to use one, my shutter speed dropped so low that the sea anemone’s slowly-moving tentacles blurred. Because of this, I positioned my camera to eliminate the reflections and took the shot without the polarizer. Even without the polarizer, the light was so low that I had to bump my ISO up to 500.
This is exactly the kind of information you will find in our Essential Filters Course. We include a variety of real-world case studies so that you can see and understand the thought process behind our on-location workflow.
Here is a short video on the same topic for those of you who like to watch videos. 😉