There are two conventions for showing movement in a still life shot, both of them approximating quite closely to our impression of seeing it. One is streak photography, in which a time explosion shows the blur of a moving object tracing the direction of travel; the other is step photography, in which a sequence of short exposures taken as the object moves also traces its path. Both need careful planning and the adjustment of light and camera settings so that the trace appears satisfactorily, and, for a conventional treatment, a well lit, sharp image of the object also needs to appear at the head of the trace.
For streak photography, a continuous light source is essential, and as the exposure time usually measure seconds, tungsten film which suffers little from reciprocity is the more useful emulsion. Streaking appears more distinctly against a dark background than against light, as the latter washes out the passing image. Exposure time, light level and rate of movement all control the length and intensity of the streak and experiment is usually necessary. Opening the lens slowly at the start while the object is already moving produces a graduated tail. Another, more controlled way of doing this is to place a black card mask close to the lens so that its edge is soft; as the moving object appears behind it, the trace is revealed gradually.
To include a full, sharp image at the head of the trace, either a timed flash exposure must be added to the sequence, or a separate exposure on the same sheet must be made, or else the movement can be reversed, starting with a static time exposure.
In many situations, it may be easier and more controllable to move the camera rather than the object, provided that the background is plain so that it shows no evidence of streaking (black, for instance). The alternatives are panning on the tripod head; tracking, which involves moving the camera on some kind of rail; or, with a view camera, winding the shift knob. Smooth movement is easier when panning than when using the other two methods; graduated scales on the tripod head, rail or camera shift make stepping easy.
Stepping sequences are most easily done slowly, under control, making, in effect, a series of multiple exposures. Graduating the exposure of each step, or the distance between them, helps the sense of movement. Precision is important. An alternative is to photograph real-time movement with stroboscopic flash, highly effective against a dark background but limited in lighting quality.
Although these techniques can be used to show the movement of a regular object, they can also be used more imaginatively, to create shapes and patterns. Curved shapes of all kinds, for example, are quite easy to produce with geometric perfection by photographing circular movement (an object or light revolving on a turntable, for instance) at different angles and with different focal lengths of lens.
Sources:
http://photo.net/digital-darkroom-forum/00GypZ
http://www.digitalcamerasdatabase.com/forum/35mm-photography-forum/5369-streak-photography.html
Written by RonaldMarbles