What you have to remember is that your vision gives you colors made up of pigment and reflections. To get “true” colors you have to remove reflection, and we have a natty filter to do just that. It’s called a Polarizer.
I have written about polarizing filters before and they are different from most other filters in the fact that they are made up of not one element, but two distinct elements. There is an outer ring that rotates the outer “glass” relative to the inner element. This increases or reduces the degree of polarization to allow the photographer an endless range of polarized effects from one filter.
What you have to understand now is that these filters remove reflections from any surface. If you cannot see through some normally transparent windows, it is because of reflected images on the surface of the glass. The reason some tree leaves appear to lose their color is through reflected light from the sky above.
One of the traps for young photographers is that because you know the grass is green, you see it as green when you look through the camera viewfinder – even though it is not truly well saturated green. Look again at the scene in your viewfinder. The green grass is really a mixture of green and silvery reflections, dark shadows and pale green shoots. Put the polarizing filter on the lens and slowly rotate the outer ring. Suddenly the silvery reflections disappear and the leaves become a deep, solid green color. The grass is now made up of green, dark green and pale green. This green will really leap out at you and smack you fair between the eyes!
Your next beach scene when taken with a polarizer will really amaze you. Again, slowly rotate the outer ring on the polarizer. Look critically through the viewfinder and you will see the sky take on a much deeper color to highlight the white clouds. Keep turning that outer ring and the sea will change to a deep blue to green luminescent hue.
Try taking the multi-hued shop houses. The colors will all be stronger. The end result is at your command. Try taking the same shot this weekend, but with varying degrees of polarization and see the differences in the final shots.
So, if the polarizer is such a wonderful bit of gear, why do we not make it a standard piece of equipment on all cameras? Well, like everything, there is a downside as well as the upside. In the case of the polarizer it does its bit of brilliance at the expense of the amount of light that gets through to the lens. With most polarizing filters you will lose about one and a half stops of light. What this means is that the shutter speed will be at least twice as long to record the same scene, or that the aperture will have to be twice the size. This means that you are more likely to get camera shake effects and suffer from lack of depth of field when using the polarizer. However, with shots in the bright sun, a commodity that is everywhere in Thailand, polarizers will bring a new dimension to your shots.
By the way, when using any filter on your camera, I suggest you use a stepping ring to increase the diameter of the filter, so there are no unwanted vignetting effects, especially with wide angle settings. My regular camera has a 55 mm diameter lens, which I have then stepped up to 62 mm so takes all my old filters. This is really a good idea and also cuts down the number of lens adapters you will need. Including the polarizer.