Soak up some rays
Mark Hamblin shows you how to get the most out of an essential component in any photographer’s kit
With the advances in postproduction software, it’s now possible to do almost anything to your images after you’ve fired the shutter, but there’s one filter that’s difficult to replicate effectively, and that’s the polariser. A polariser has many uses, but its primary function is to reduce the amount
Two types of polariser
The most common type of polariser is the circular screw-in type made by the likes of Hoya and B+W. These come in various diameters, and you’ll need to buy one for each size of lens you own. A slot-in polariser, such as from Lee or Cokin, is used with a filter holder.
When to use one
A polariser is typically used when shooting in bright sunlight, but it can also be effective in overcast conditions to increase saturation, although the results tend to be more subtle. A polariser reduces the amount of light reaching the sensor by upto around two stops. of glare from non-metallic reflective surfaces such as water. It also removes the small reflections from leaves and other foliage, saturating the colour and giving the landscape extra punch. Its other main use is for intensifying the colour of blue skies and making white clouds stand out. A polariser also helps to reduce atmospheric haze.
How to use one
The effect of a polariser can be seen by rotating the filter on the front of the lens or in the holder. The degree of polarisation depends on your shooting position in relation to the angle of sunlight. It’s most noticeable when you’re photographing at a right angle.
Watch out for…
Polarisers often produce uneven results when using a wide-angle lens because some parts of the sky are more polarised than others. It’s most noticeable in a blue sky, with the more polarised area appearing darker. The effect can be lessened by increasing the focal length.