Pixiq

We have all done it: seen something that catches our eye on route to the main target and taken a hurried shot without checking the background. Yet sometimes it really pays to check a shot with the depth of field preview before moving on.

With either a long lens and a narrow angle of view or a longer macro lens, it only takes a small movement sideways, up or down to correct the problem.

When shooting wildlife or macro subjects there is nothing to beat using a fast lens to gain a soft out of focus background, but when you have a 3D subject that needs a smaller aperture to get everything in focus, that's when problems may arise.

Here are three examples of an unspectacular (but abundant) plant that grows as the shrub understorey in the tall karri forests in south-west Australia. When in focus, the fine cream flower head of karri hazel merges in with others close behind (left). It is marginally better when other plants are further behind so they are completely out of focus (center) but similar tones tend to merge. The best way to isolate any plant with a mass of tiny cream or green flowers is to look for tonal separation. I moved around until I found a flower spike sticking out sideways with a dark patch behind it.

Another example, also taken in Australia, shows an erect sundew. This insectivorous plant was taken late in the day when the sticky tentacles used to ensnare insects, were glowing with the low angled late sun (left). I knew the background simply did not do justice to the stunningly lit plant, so I brought out my portable black velvet background wrapped around a piece of board and propped it up behind the plant and used the same manual exposure because the light had not changed (right), but a lower camera angle to get the sensor plane parallel with the plant so all the leaves could be brought into focus. The lighting is completely natural and while this background has been added, the same effect can be gained from a shadow cast by an upright rock – or indeed a judiciously placed photo pack.

Here is one such scenario showing a star clover with attractive red bracts that remain after the central flowers wither. The first shot was taken in sunlight (left), then using exactly the same light and manual exposure (right) I got a companion to cast a shadow behind the flower. You can direct where they should stand, but they have to concentrate and not move their arms around so as to cast an unwanted shadow on the subject!

Also look out for the reverse effect of tonal separation, whereby the subject is in shadow or not so well lit as a brighter backdrop. I spotted the great blue heron at first light against the brightly lit snow and ice, which isolated not only the bird but also its prey far better than against reeds in spring or summer.

The leaping jackdaw was a lucky grab shot, once again taken at first light.

A silhouette is an extreme example of this kind of separation – although this then provides no information about color or texture of a subject.