Monday, July 25, 2011
First Circular Polarizer Photo
VIA 6420 leads VIA 6407 and the rest of VIA 693 (the Hudson Bay) out of Winnipeg, Manitoba.
This is my first shot with my new circular polarizer.
What does a polarizer do? Well... it's hard to explain and I don't totally understand it. Sunlight is unpolarized, meaning that the light waves vibrate in a variety of directions ("planes"). However, sunlight that reflects off a nonmetallic object is polarized. A polarizing filter only allows a certain "plane" of light through. Turning a circular polarizer adjusts what "plane" of light is allowed through to the camera, so reflections can be blocked.
The end effect is that contrast is higher (skies are darker, for example, as you can see above). Also, a polarizer can help cut through haze as much of the haze is reflected light.
There are some interesting images here showing the difference between non-filtered and filtered images.
PhysicsClassroom.com has a good tutorial on polarization of light.
I bought a Hoya PRO1 58mm polarizer. There are cheaper polarizers, such as this Hoya model. The differences include multi-coating (to reduce lens flare) and construction (plastic vs. metal frames). It's all in what you are looking for.