The use of computer graphics in wildlife film productions can help depict the natural world in ways that go beyond what the naked eye or even the best cameras can perceive. Computer generated images (CGI) compositing and the re-touching of images can sometimes give a useful and illuminating perspective on how the natural world works. These techniques are used sparingly in wildlife films.
CGI can show things that it is impossible to visualise with a camera, but are important to understanding the behaviour of particular animals. Life in Cold Blood used this technique to show the changes that take place inside a python when it is digesting a large meal.
Frozen Planet used CGI to animate the data from satellite imagery to show changes in sea ice cover for the polar regions.
Compositing is a technique widely used in Hollywood. It involves live-action with real actors being shot against a single colour (monochromatic) screen – usually blue or green.
This footage is then composited onto a background, or "backplate", which might be an entirely computer generated image, or one shot at another location.
This technique is not widely used in most BBC wildlife programmes, but the unusually stylised Hidden Kingdoms series made much of this technique while dramatising the lives of its little animal characters.
There are rare occasions in classic wildlife films when plant or animal action also has to be filmed in highly controlled settings, against blue screen, because it would be impossible to film them on location. But to make the point that this activity is natural, filmmakers still want to indicate how it would look in the wild. The Plants episode of Life was one of these rare occasions.
Sometimes an unwanted, manmade feature finds its way into a beautiful shot of nature, for example a plane's "jet stream" appearing in a stunning timelaspe of the sky. Filmmakers may judge such features are a destraction and remove them.
There are other manmade objects that are unavoidable when filming animals, for example radio collars.
Scientist often fit wild animals with tracking devices – like GPS collars – to better understand their behaviour and this presents a valuable resource for filmmakers to find and film them.
Where possible these collars would be shown in a finished film, but in some circumstances a collar might be painstakingly erased for continuity purposes. Partnerships with cutting edge science like this enable us to show more and more surprising new behaviour to audiences.