WHAT DO POLARIZED SUNGLASSES DO - POLARIZED SUNGLASSES DO

What do polarized sunglasses do - Celebrity sunglasses 2011 - Mirrored lens sunglasses

What Do Polarized Sunglasses Do


what do polarized sunglasses do
    polarized sunglasses
  • Sunglasses or sun glasses are a form of protective eyewear designed primarily to prevent bright Sun light and high-energy visible light from damaging or discomforting the eyes.
  • These should be worn when fishing in bright sunlight to cut down on the glare from water.
  • Polarized sunglasses reduces glare from the sun and allows the angler to view into the water. They work on the principle blocking the horizontal polarized light reflections by the vertically oriented polarizers in the lenses.

Cross Polarising
Cross Polarising
Imagine now, if you will, what would happen if you were to put another set of bars, rotated 90 degrees in relation to the first set of bars. In theory, none of the ice-cream sticks would get through, right? Well, that’s how Polarizer filters work, too. Of course, no polarizer filter is perfect, so some light will always get through, but the vast bulk of light is filtered out. Cross-polarization exploits this by placing objects made of some types of plastic between the first and the second polarizer. For this particular set-up, you’ll want to put your first polarizer in front of the light source, then your plastic object, and then use the second polarizer in front of your lens. The effect that can be seen when cross-polarizing light is startling. Chances are that you’ve seen cross-polarized images before, and thought that they were digital image manipulations or done with really advanced lighting. The opposite is true: Due to the manufacturing process used in creating injection-moulded clear plastics, the plastic takes on some ability to polarize light itself. When the polarized light passes through these plastics, then, their phase gets altered. By filtering out all other light with the second polarizer, you get the colorful, acid-flashback-style images. Light reflected by shiny transparent materials is partly or fully polarized, except when the light is normal (perpendicular) to the surface. It was through this effect that polarization was first discovered in 1808 by the mathematician Etienne Louis Malus. A polarizing filter, such as a pair of polarizing sunglasses, can be used to observe this effect by rotating the filter while looking through it at the reflection off of a distant horizontal surface. At certain rotation angles, the reflected light will be reduced or eliminated. Polarizing filters remove light polarized at 90° to the filter's polarization axis. If two polarizers are placed atop one another at 90° angles to one another, there is minimal light transmission. Polarization by scattering is observed as light passes through the atmosphere. The scattered light produces the brightness and color in clear skies. This partial polarization of scattered light can be used to darken the sky in photographs, increasing the contrast. This effect is easiest to observe at sunset, on the horizon at a 90° angle from the setting sun. Another easily observed effect is the drastic reduction in brightness of images of the sky and clouds reflected from horizontal surfaces (see Brewster's angle), which is the main reason polarizing filters are often used in sunglasses. Also frequently visible through polarizing sunglasses are rainbow-like patterns caused by color-dependent birefringent effects, for example in toughened glass (e.g., car windows) or items made from transparent plastics. The role played by polarization in the operation of liquid crystal displays (LCDs) is also frequently apparent to the wearer of polarizing sunglasses, which may reduce the contrast or even make the display unreadable. Polarizing sunglasses reveal stress in car window (see text for explanation.) The photograph on the right was taken through polarizing sunglasses and through the rear window of a car. Light from the sky is reflected by the windshield of the other car at an angle, making it mostly horizontally polarized. The rear window is made of tempered glass. Stress in the glass, left from its heat treatment, causes it to alter the polarization of light passing through it, like a wave plate. Without this effect, the sunglasses would block the horizontally polarized light reflected from the other car's window. The stress in the rear window, however, changes some of the horizontally polarized light into vertically polarized light that can pass through the glasses. As a result, the regular pattern of the heat treatment becomes visible. you get the colorful, acid-flashback-style images.
Cross Polarising
Cross Polarising
Imagine now, if you will, what would happen if you were to put another set of bars, rotated 90 degrees in relation to the first set of bars. In theory, none of the ice-cream sticks would get through, right? Well, that’s how Polarizer filters work, too. Of course, no polarizer filter is perfect, so some light will always get through, but the vast bulk of light is filtered out. Cross-polarization exploits this by placing objects made of some types of plastic between the first and the second polarizer. For this particular set-up, you’ll want to put your first polarizer in front of the light source, then your plastic object, and then use the second polarizer in front of your lens. The effect that can be seen when cross-polarizing light is startling. Chances are that you’ve seen cross-polarized images before, and thought that they were digital image manipulations or done with really advanced lighting. The opposite is true: Due to the manufacturing process used in creating injection-moulded clear plastics, the plastic takes on some ability to polarize light itself. When the polarized light passes through these plastics, then, their phase gets altered. By filtering out all other light with the second polarizer, you get the colorful, acid-flashback-style images. Light reflected by shiny transparent materials is partly or fully polarized, except when the light is normal (perpendicular) to the surface. It was through this effect that polarization was first discovered in 1808 by the mathematician Etienne Louis Malus. A polarizing filter, such as a pair of polarizing sunglasses, can be used to observe this effect by rotating the filter while looking through it at the reflection off of a distant horizontal surface. At certain rotation angles, the reflected light will be reduced or eliminated. Polarizing filters remove light polarized at 90° to the filter's polarization axis. If two polarizers are placed atop one another at 90° angles to one another, there is minimal light transmission. Polarization by scattering is observed as light passes through the atmosphere. The scattered light produces the brightness and color in clear skies. This partial polarization of scattered light can be used to darken the sky in photographs, increasing the contrast. This effect is easiest to observe at sunset, on the horizon at a 90° angle from the setting sun. Another easily observed effect is the drastic reduction in brightness of images of the sky and clouds reflected from horizontal surfaces (see Brewster's angle), which is the main reason polarizing filters are often used in sunglasses. Also frequently visible through polarizing sunglasses are rainbow-like patterns caused by color-dependent birefringent effects, for example in toughened glass (e.g., car windows) or items made from transparent plastics. The role played by polarization in the operation of liquid crystal displays (LCDs) is also frequently apparent to the wearer of polarizing sunglasses, which may reduce the contrast or even make the display unreadable. Polarizing sunglasses reveal stress in car window (see text for explanation.) The photograph on the right was taken through polarizing sunglasses and through the rear window of a car. Light from the sky is reflected by the windshield of the other car at an angle, making it mostly horizontally polarized. The rear window is made of tempered glass. Stress in the glass, left from its heat treatment, causes it to alter the polarization of light passing through it, like a wave plate. Without this effect, the sunglasses would block the horizontally polarized light reflected from the other car's window. The stress in the rear window, however, changes some of the horizontally polarized light into vertically polarized light that can pass through the glasses. As a result, the regular pattern of the heat treatment becomes visible.

what do polarized sunglasses do
Comments