Take a landscape lit by strong sunlight, only a few wispy clouds in the sky. The range of brightness will be quite high, from deep shadows, to white painted cottages lit directly by sunlight. The sparkling reflections off water we probably need not worry about, since they usually look fine as burnt-out specks. When the weather changes and the landscape is lit only by a dull, grey sky, the range of brightness will have reduced considerably. There will be no sunlit bright highlights and the shadows will be filled in a little by the evenness of light from the sky. Ironically, and much about photography is ironic, the bright sunny day provides plenty of light for us to use slow film to photograph the scene, but the wide brightness range is difficult for the film to handle. The dull day, however, which can be handled by the slow film, has little light.

What can we do about it? Firstly, we have to stop looking at the amount of light we have and start thinking about its quality. Take the sunlit scene. One of the qualities of the light is harsh, high contrast. To match the limitations of the film to this harsh quality, we could use a high speed film and gain the added benefit of increased depth of field with a small aperture. We could expose more for the shadows and reduce the development to stop the highlights blocking-up. Or use filters, either yellow, orange, red or polarizing, to reduce the brightness of the blue sky, although they can cause more problems by increasing its contrast with any clouds. Colour and grey graduated filters can be useful, if used carefully. If the main problem is with deep shadows in the close foreground, then a reflector may help to get some light into them or even use fill-in flash. We could use a combination of all of them, depending on the situation. What about the dull day? Well, one of its qualities is low contrast. Using a slow film, with its higher contrast, will help to balance that. Use a tripod to avoid camera shake with slow shutter speeds, most landscape photographers do, and any slight blur of movement in the scene may add to the effect. On the other hand, you could use a faster film, increase the development to push it and increase the contrast. The polarising filter will not be of use because the light from the clouds isn't polarised. Similarly, the colour filters will do little or nothing to a sky that is basically shades of grey. The graduated filters, particularly a grey, can be used to darken down an over-bright grey sky.

Remember, although it will often be a compromise between the two, when it comes to light, quality is usually a great deal more important then quantity.

At the beginning I mentioned transparences hitting the bin. Much of what I've said about B&W negative film, applies to colour transparency film (slides) as well. Colour filters can't be used to affect contrast so easily, but a polarising filter, as well as colour and grey graduated filters can be. Transparency film can also be pushed and pulled to great effect and allows more control over the final image. Try it. Increasing the exposure and then pulling a stop or two lowers the contrast and reduces the strength of the colours, while reducing the exposure and pushing does the reverse. If you use the lovely Kodachrome, you need to check with Kodak what they offer and what extra charges there may be. If you use E6 process film, then you will probably need to take it to a professional lab, which may or may not charge extra. Always explain what speed you have rated the film at and don't do it with anything important until you know what to expect. If there is one big secret of the professionals, it's test, test and test again, before doing the real thing.

© Barry Leighton FRPS