Читать книгу Collins Complete Photography Projects - John Garrett - Страница 40

In the pre-digital days of shooting on colour transparency film, professional photographers carried around a large selection of light-balancing filters to correct the colour casts in single and mixed light sources.

With the technological advances in digital cameras, those filters attached to the front of the lens have largely become obsolete; most cameras now have built-in digital filters to simulate the effects they gave. Generally, these can only be applied via the retouch menu after the picture has been taken. Post-processing on the computer also provides the ability to adjust colour casts.

The two on-the-lens filters we still recommend you carry are the graduated neutral-density filter and the polarizing filter, especially when you are shooting landscapes. The ‘grad’ filter, which is available in varying densities and colours, will allow you to retain detail or exaggerate the sky tone in a landscape where the sky would be overexposed. This effect can also be done in the computer using Photoshop, but it requires some skill. Using a grad filter on the lens will give you an instant result. A 2-stop neutral density (grey) graduated filter is a good one for general use.

The polarizing filter is often used to darken blue skies and thus make the cloud formations more prominent. While that can also be achieved in Photoshop, where the polarizer comes into its own is in reducing or eliminating unwanted reflections from water, glass and non-metallic surfaces, which cannot be done on the computer.

QUICK TIP

Adding a diffusion or softening filter on the lens can be flattering for portraits, giving them a glow and smoothing detail. A similar effect can be added later in Photoshop or in Lightroom using the Clarity tool. Also try breathing on the lens to mist it up before you shoot – it can produce a very soft effect.

FILTERS

Shown here are a polarizing filter (bottom left), graduated filters (top left and right), and the lens mount (bottom right).

UNFILTERED

In this unfiltered landscape shot, the sky has been overexposed because the landscape, which occupies most of the picture, is darker than the sky. The camera is unable to handle the major difference in exposure. 1/250 second at f11, 75mm, 400 ISO. GH

NEUTRAL DENSITY FILTER

Here, the neutral density filter has been slid over the sky area, slightly cutting into the horizon line. This has enabled the capture of detail in the sky that was visible to the human eye. 1/250 second at f11, 75mm, 400 ISO. GH

UNFILTERED

In this photograph taken without a polarizing filter, the sky is reflecting in the water. The water is impenetrable, resembling opaque glass. 1/250 second at f6.3, 29mm, 400 ISO. GH

POLARIZING FILTER

Here a polarizing filter attached to the front of the lens was rotated to a position where it cut out the reflections of the sky, allowing us to see below the surface of the water. 1/30 second at f6.3, 29mm, 400 ISO. GH