CONTROL COLOUR

Use filters to adjust or enhance the chromatic balance of a scene

One of the first things we learn as digital photographers is that shooting with the camera in RAW mode is the first step to professional colour control. Unlike a jpeg file, a RAW file is uncompressed and so contains much more digital information.

This provides scope for better colour adjustment in photo editing software, enabling you to change the white balance after the shoot is over. While many photographers choose to leave colour control to the postprocessing stage, just like exposure, not all effects can be simulated at the computer.

The most well-known filter, which falls squarely into this category, is the polarising filter. It is seen by many landscape photographers as an essential addition to any professional’s kitbag because the optical effect it applies is unobtainable using any other method.

Since the characteristic saturation of blue skies and removal of reflections that the polariser provides is achieved using physical modification of the ambient light, no postprocessing tool can reproduce the result.

Hardware filters can have other, lesserexplored functions too. The polariser works by using a microscopic mesh to prevent the passage of light waves vibrating in a selected direction. Rotating the filter in one direction cuts out polarised light from reflective surfaces, while turning it the other way can actually seem to enhance the visibility of reflections. It is an illusion – no filter can increase light transmittance – but this effect is useful when shooting reflections in bodies of water or glass-covered buildings.

While colour has never been easier to control after the shoot, having a set of filters can be your secret weapon. The types described here allow you to apply effects at the shooting stage, which can streamline your workflow, increase productivity and introduce special effects that are challenging and timeconsuming to simulate in software.