Canon Professional Network presents how to choose and use the right filters for creative DSLR filmmaking :
'With the advent of video capture on DSLR cameras the craft of cinematography has moved within the reach of many of those who previously just thought in terms of stills. Carey Duffy (Technical Director of filter company Tiffen in the UK) writes for CPN on what to look for when selecting the right filters for photography and filmmaking...
Prior to the HD video revolution, shooting professional quality motion images was only possible with the use of either a broadcast video camera or a 35mm or 16mm motion picture film camera. For the still photographer the investment to enter this area would have been huge but now technology has opened up the field to a whole new audience, who are having to learn the practical skills required to enter this emerging sector.
The first thing to realise is that, despite apparent similarities in what you are trying to achieve, the techniques you need to master to tackle cinematography and still photography are quite different. Understanding why these differences exist and what is required at a basic level to enable competent recording of an image will always be fundamental to each of these crafts.
For example, a cinematographer may have to consider the changing light conditions that will occur during a camera movement. Add that to the need for continuity as a basic requirement of storytelling and it starts to become clear why cinematographers find themselves having to work to a discipline which is very different to that faced by the still photographer. Exactly how a story is produced and told with a moving camera is defined by the cinematographer’s choice of tools, and there are many specialised products that are dedicated to the video-enabled DSLR to help you get the best results.
Filters are one of the many tools that both a photographer and a cinematographer employ to control the light entering the camera lens, either as a physical necessity, for aesthetic effect or even to achieve both these ends. A good tripod, lenses and a few other tools are likewise common in both disciplines. However, when shooting movement there is a physical difference from stills, in that a constant shutter speed has to be used. Then the question of how to control the intensity of light, especially for exterior shots, means that the use of filters as a primary tool becomes paramount.'
You can read the entire article on the CPN website here.