CPL polarizer is sandwiched by the two optical glass has a directional effect of the polarization properties of tiny crystals (such as mica) composed by rotating the lens can eliminate the subject surface polarized reflected light.
Depending on the mechanism of polarized light filter, polarizer can be divided into circularly polarized light microscopy (abbreviated CPL) and the linear polarizer (referred to LPL) are two, these two effects are the same .LPL mainly used for old-fashioned manual focus cameras.
Many things will be reflective: sky, ground, water, glass, smooth desktop, including flowers and trees and human skin, etc., relatively smooth surface will reflect light to shoot these objects when you need to use a polarizer is theoretically? Thus, especially in the shooting or below the surface of the glass in the window object, the polarizer can be described as essential for indoor lighting, polarizer can also play the same effect. use polarizer can eliminate wooden tables and other non-metallic surface reflective properties, filtering Desktop reflected light, but there is no effect on the reflective metal, both to avoid the impact of the desktop reflective subject, in turn metalware texture demonstrated.
When shooting in strong sunlight, because the sky, the ground, especially asphalt easily reflect sunlight, so it is best to shoot plus polarizer.
Cloudy shooting polarizer is also useful because cloudy sky can be seen as a huge light, smooth surface will be reflected sky light. If you do not want these light remain in our photo, you Polaroid lens should be used.
Note: When using polarized light microscopy, due to the need to rotate the filter, inconvenient to use the hood, we should try to shoot the camera in shadow; after installing a polarizer, will reduce the amount of light through the lens, the automatic mode, aperture priority and shutter priority The camera mode will make their own adjustments, but if it is, then we should pay attention to the manual exposure adjust exposure compensation. From this point on, the polarizer at some time can also be used as a last resort by light microscopy to use. roughly equivalent ND4 effect.
PL polarizer and the reflecting surface (glazing or water) into a 30-40 degree angle to use in the elimination of reflection to get maximum effect, while a 90-degree angle (straight to the reflecting surface) Use effect little or no effect.
In order to increase the concentration of blue color, PL when the sun is 30-40 degrees in the sky, while the camera directly to the sun polarizer to obtain maximum results. Midday sun or the results of a 90 degree angle with the ground in the head, then polarizer minimal effect. These effects from the camera's viewfinder is very easy to see. Check the effect by simply rotating polarizer