Polarizing Filter Lens

Polarizing Filter Lens

What Are Polarized Sunglasses?

When sun light gets reflected from flat surfaces like flat road, water or snow, it produces glare. This glare effect affects the eyes particularly when you are involved in driving or any other kind of outdoor sport. The glare makes you feel annoyed and will divert your concentration. Polarized sunglasses are manufactured to absorb the solar glare. These glasses are able to absorb up to 97% of the glare.

The iris present in the eyes shuts down automatically when exposed to intense light or glare. But it gives strain for the eye when the intensity is higher. Use of polarized sunglasses will almost nullify the strain of the eye as it almost eliminates glare.

Polarized lenses were by invented Edwin H. Land in 1936. The characteristic of light is that, it travels in the form of waves and vibrates in all directions. When this light is reflected by any flat surface, the vibrations are oriented in the horizontal direction. To neutralize this, the polarized lenses make the light to vibrate in the vertical direction, thereby stopping the vibration and reducing the glare.

Polarized lenses are made with light weight plastic materials. The common plastic used are CR-39 or polycarbonate. These have a polarization filter enclosed. These polarized lenses are also available as designer sunglasses. So you can look trendy as well as can have a clear vision free from glare.

Many well known brands manufacture quality polarized sunglasses but are priced high. Look alike polarized sunglasses are available in the market at lower prices. It is always advisable to choose branded polarized sunglasses as quality is assured. The genuineness cab be tested by rotating the polarized lenses in one direction and check if the intensity of the glare through the lens changes. A duplicate might damage the eyes and so it is better to invest some bucks to protect your eyes with branded polarized sunglasses.

People who suffer from eyesight problem such as myopia or hypermetropia or even presbyopia can make use of polarized lenses and enjoy their thrill packed adventurous game.

Polarized sunglasses have disadvantages on their negative side. As they block the reflecting rays, certain relief features in the snow may not be visible. This becomes a serious problem when you are involved in snow skiing. Also at certain angles, they make LCD displays invisible as LCD is also polarized light. While driving, many displays in the car and on the roads are LCDs only.

The advantages of polarized sunglasses overcome the shortcomings. It is highly essential to wear polarized sunglasses when involved in outdoor sport and you can get one starting from 75$ to 300$ with different brands.

About the Author

Buy Designer Sunglasses at http://www.spectglasses.com , A venture from Status Eye Care, Opticians in Mumbai. For More Information Visit http://www.statuseyecare.com. Looking For Freelance Writer. Look No Further... FCWS Freelance Content Writer Services are pioneer in Content Writing since past 5 years. We provide Search engine Friendly articles at Lowest Rates. We have provided more than 50000 articles with more than 800 satisfied clients. We Have Expert Writers For All the Niches Like Travel Writer , Health / Medicine Writer , Internet Marketing / SEO Article Writer, Interior Designers, Finance and Business Writers and Many More. Visit our site http://www.contentwriter.info

Should I get a polarized lens filter for my camera?

I have a Canon xti with the standard 18-55mm lens that came in the kit. The guy at the camera store tried to sell me a polarized Tiffen filter, which I didn't buy. Now I'm considering it. Is it necessary, and if so, what are the benefits? What are negative things that can come from using it? Can it be left on at all times for all shooting conditions? Right now I just have a hood, but am considering returning it for the filter. Any advice on what to do and what positive and negative effects the filter could have would be great.

Short answer: You don't need it.

A CPL (Circular Polariser) allows you to filter out polarised light. Effectively this lets you do several useful things:

It can make a sky turn a darker blue.
It can take the reflections off water, glass and reflective surfaces.
It also limits your light gathering ability so it can be used as a makeshift ND filter if you need one in a pinch.
It can also sometimes slightly alter the colour of other things such as foliage.

When using a CPL to darken skies, the effect is greatest when shooting at 90degrees from the sun. A word of warning: do not use a CPL to darken skies when using a lens any wider than your kit lens. This rarely gives anything other than a very uneven effect as the angle of view is too wide.

In some cases a CPL is a MUST, like when you need to reduce reflections but it's not an essential piece of kit unless you have the specific needs mentioned above.

I definitely wouldn't recommend leaving it on the lens all the time. All filters cause glare and ghosting, which can degrade your images and even show up as bright lights in your shot, especially when you have a strong light source in the shot.

If you want something to leave on your lens as protection, buy a good quality multicoated UV filter. Hoya are good. However, even very expensive filters can cause some glare, etc.

One thing you should know if you decide to get a CPL is that it won't totally remove strong reflections from flash. Flash is pure non-polarised light and isn't affected until it's been polarised. If you do ever need to do such things then a second polariser can be fitted over your flash at 90 degrees to the one on your lens to give a flash lit picture with very little reflections, even when photographing things such as water.

Out of all these uses for a CPL, reducing reflections is the only one that can't be done in post processing. For this reason, the CPL (along with ND filters) are amongst the few filters that are still useful in the digital age.

Goodluck!

EDIT: Holly9's answer is partly incorrect. All filters, especially cheap filters and especially in bright sunlight can and will harm image quality. So even if you keep a UV protection filter on your lens, it is wise to remove it for important shots where there are bright light sources.

Also, Holly9s comment about UV filters filtering out UV light is also incorrect. Unlike in the film days, modern digital sensors are built with filters which block out almost all UV light. So a UV filter does nothing, at least not to UV light.

SAL50M non rotating front lens & polarizing filter