Wonderworld of filters
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No matter how extensively and conveniently photos can be manipulated using image programs, information that has not been captured cannot be conjured up by software. Corrections damage the data set by subtracting information – which is recognisable by the gaps in the histogram. The losses are almost imperceptible on a PC monitor, but
become evident on high-resolution print-outs and larger formats. There is an unbelievably large selection of filters and hence also effects. The classic among them is without doubt the polarisation filter: it is universally suitable for fair-weather photography, removes the grey-blue haze on sunny days and allows all colours to glow more purely, especially sky blue. Pol filters can be rotated in the mount to regulate their effect. They work most effectively when the sun is at a (slight) angle and at right-angles to
the sun. For the Olympus E-System you should use circular pol filter models as, unlike the less expensive linear version, these do not confuse the exposure. In addition, pol filters reduce reflections on non-metallic surfaces such as glass or water. A creative highlight for black and white fans is without doubt the infrared filter, as shown in the large photo on the left. As infrared produces distortion in normal colour photography, Olympus E-System cameras are fitted with internal IR blocking filters which permit almost no infrared light to pass through to the image sensor. Infrared filters are different – they filter visible light and only let infrared through. Therefore, a very small percentage of light remains behind both filters to produce 100 percent image. For this reason the exposure time is increased considerably. IR photos work best at noon on sunny days.
Important tips: use a strong infrared filter that allows no visible light to pass (e.g. B+W IR 093 or Heliopan RG 780). Activate the noise reduction filter on your E-System camera. Perform the white balance manually with the filter. The picture can now be controlled from the tripod and focused initially without a filter. Focus manually a short distance behind the main subject as the IR focus point is in front of the light that is visible to you. Expose with the filter screwed on and aperture 7.1 to 8 for about 10 seconds at ISO 200. Check the reddish image on the monitor for sharpness with the magnifying glass function. Experiment – it’s worth the effort! |
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WHICH FILTER AND WHEN
- Soft focus filter: flatters any skin in portraits
- Grey filter: balances exposure contrasts
- Protective filter: good for the lens
- Pol filter: more colour, fewer reflections
- Graduated grey filter: reduces extreme contrasts
- Infrared filter: a creative highlight (see large photo)
- Redhancer: makes red tones glow
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Photo artist STEVE BISGROVE took this picture in the grounds of Villa Melzi, Ballagio, at Lake Como (Italy): “When I shoot infra-red I’m looking for locations that have
some mystique: and aren’t overcomplicated (and I go for a simple composition too) – sweeping landscapes would be rather flat and uninteresting shot in infrared.
There is generally more infrared light around in the summer during hot weather, but duller, cloudy conditions, when temperatures are cooler, and the light is soft with indistinct shadows produce much more satisfying results. This shot had dark green lawns and gravel paths. Strong elements that in colour would have dominated the statue and gazebo. The mist shrouding the mountains in the background is accentuated with the infra-red, which invites the viewer to look on past the foreground objects and delve farther into the picture.”
– More from the Rome-based Briton at http://www.stevebisgrove.com/ |
