Make colours pop!
Six polarising filters tested
Truly multi-functional, the circular polariser is a favourite filter for photographing in a wide range of situations. Let’s start with the science bit, because it’s important to know what makes a circular polariser ‘circular’, and why it’s different from a linear polariser filter. Both types contain a linear polarising element which, when rotated, can absorb varying amounts of polarised light in a scene. However, a circular polariser filter has an additional ‘quarter wave plate’, so that light emitted by the filter is circularly polarised. This is necessary so that the autofocus and metering systems of D-SLRs can function correctly.
In landscape photography, circular polarisers are often used to darken blue skies while giving greater differentiation between areas of clear and cloudy regions in the sky. They can also give greater colour saturation and contrast, while reducing reflections from non-metallic surfaces. This can be a big bonus for cutting glare from watery surfaces and revealing the beds of ponds and rivers, as well as for shooting through windows.