polarizing filters are something that pretty much all of us own as photographers. It may not be something we really use all that often, but most of us have at least one somewhere in our pile of camera bags filled with gear. But what exactly is polarized light? And how can we used to go beyond the usual popping of skies and foliage in landscapes?
Well, in this video from The Science Asylum, we take a deeper look into light polarization. We learn about what it is, how it works and how we can utilise it along with polarizing filters in order to see things that would otherwise be invisible to the naked eye.
In essence, light basically flies off and bounces in all directions from its source. Polarized light is some of this light which is flying in a particular direction. A polarizing filter (or polarized sunglasses) allows us to see that light travelling in that specific direction and we can adjust the direction by rotating it. This is what makes them ideal for photography, allowing us to remove things like unwanted reflections from glass surfaces and the reflections of the bright sky from green foliage to produce deeper, richer and more saturated landscapes.
You can really see the more extreme effects of polarization when you combine two of them, though, as demonstrated in the video. This is also basically how most variable ND filters work – two polarizers, working against each other in order to darken down the image to some degree. In fact, there’s a demonstration in the video which demonstrates pretty much the exact principle upon which most variable ND filters are based.
Cross polarization also offers some other hidden benefits, too, though. It allows us to see things that would be otherwise invisible to the naked eye. Like the internal stresses of glass and transparent plastics. It’s a very cool effect and one that can not only make for some great photography but also help us to learn more about engineering and the internal stress distribution of different materials and manufacturing techniques.