The following is an extract from his book. This week, in Part 1, he deals with types of fog and the opportunities these present for photography. Next week, in Part 2, he will consider the technical aspects when photographing landscape in these conditions.
Even the most inexperienced landscape photographers rise to the challenge when experiencing a typical "pea-souper". Fog is caused by minute droplets of water in the atmosphere, although it can sometimes be confused with smog, which tends to occur only in heavily industrialised areas. Fog is defined as having a visibility of less than 1,000 metres, but for the purposes of photography, a reduced density of 100 or even 50 metres offers the most interesting opportunities. The incidence of fog occurs as a result of a variety of reasons, and being able to predict it certainly offers advantages.
The most common of fog is known as ‘radiation fog’ and this usually occurs during the winter and when the air is still. As the air cools overnight close to the surface, it is less able to absorb moisture so, consequently when you wake up in the morning you are greeted by a low-lying blanket of fog. It is important that you are able to anticipate its formation because it can evaporate quite quickly once the sun starts to rise.
The effects of ‘valley fog’ are not dissimilar to radiation fog. As its name would suggest it tends to occur in the bottom of valleys particularly when there is a temperature inversion, i.e. the air at the bottom of the valley is colder than the air directly above. Such fogs can last for days.
Coastal fog or sea fret
The third likelihood of fog occurring is when warmer moist air passes over a very cold surface for example when air off the sea passes over land covered by snow. Similarly, a coastal fog (or sea fret) occurs when warm moist air is blown over cooler water. The important point to remember is that, however the fog is formed, it offers amazing photographic opportunities.
The photographic opportunities offered by fog are considerable
1. As fog tends to considerably reduce colour saturation, a much stronger emphasis is placed on the tonal values. One often finds that images taken in fog can be very successfully converted to black and white. If you retain your photograph as a colour image, the hues will appear wonderfully subtle.
2. When photographing in fog you are able to explore a visual phenomenon known as ‘tonal recession’. What this means is that distant objects appear considerably lighter than those nearer the camera; this is especially apparent when photographing a forest in mist. The tonal interplay between the trees in the distance and those nearer the camera can prove particularly evocative.
3. Because of the reduced visibility, the images captured tend to be much more simple and graphic in nature. Trees and wooded areas in general lend themselves particularly well when photographed in fog.
4. Often overlooked but, if you are able to photograph fog or mist at night, you should be able to capture images rich in atmosphere. Artificial lights that normally appear too bright are tempered by the mist or fog, creating quite ethereal effects. As the ground is likely to be wet, it is possible to capture beautifully subtle reflections. As the mist swirls around the sources of light, the rays are subtly distorted, creating almost dream-like scenarios.
5. Photographed at night or in daylight, the urban landscape can appear especially interesting when photographed in mist. Traffic, only visible by dipped headlights, appears to amble through the silent, monochromatic streets offering strange and enigmatic photographic opportunities. Buildings receding into the distance can appear alarmingly unfamiliar. One has only to consider those highly evocative movies of the 1940s and 50s to appreciate the potential that this sort of lighting has to offer.
6. Look for subtle silhouettes. Fog has the capacity to simplify forms and reduce texture. Consequently, objects, even those relatively close by, appear almost silhouetted. From a visual standpoint a scene blanketed in mist undergoes a process of simplification.
More next week!
Photographing Landscape Whatever the Weather by Tony Worobiec is available from Amazon and all good bookshops.