The technique of film editing (1958)

(shots 12-13) and therefore make it doubly effective. At the same time the idea has been introduced naturally, with no discontinuity in the argument. With this point made, it only remains to ram it home by repeating it with two more examples (14-15 and 16-20). It may be objected that we have said altogether too much about this sequence, that the details we have discussed are all small, unimportant points. But it is precisely through this minute accuracy of presentation that a teaching film achieves its effect. It is most important that every point should be made clear : if the presentation slurs over only a small portion of the argument, the spectator may still be able to understand the whole film, but conciseness and complete conviction will be lost. Something should here be said about the timing of shots. The aim should be to strike a balance between not leaving enough time and making the film difficult fo follow, and giving too much and making it dull. The danger of making a teaching film dull is a very real one : as a subject develops it tends to get more complex and the cutting rate must be reduced. The film, in exact contrast with the usual story-film practice, may then tend to get slower towards the end, a difficulty which can generally not be avoided. Further than this it is impossible to generalise : correct timing is largely a matter of experience and close observation of the results of previous films. 183