Qualities Sacrificed to the Film
First, one loses excess meaning —meaning in excess of what the film expresses and requires. This is not merely what remains unexplored in the subject that can still be found in the rushes, but all material which escapes from what might be called the "economy of signification" of the film.
Second, there is a loss of interpretive space —a closing-off of the legitimate areas in which the viewer is invited to supply meaning. The film dictates a certain standard of relevancy. As it moves toward its final form, the background around the centered subject is gradually whittled away. This controls the viewer's relationship to the footage in two ways: first, the background is made to appear incidental and subservient to what the film designates as a sufficient reality. Second, the background itself is physically thinned out by cutting, thus further reducing the opportunities for "irrelevant" intervention. Although different films provide different kinds of interpretive space for the viewer, this space often merely allows the audience to endorse the film-maker's meaning rather than to participate more actively in creating it. Viewers of rushes, by contrast, constantly interject their own interpretations.
Third, there is a loss of the sense of encounter . As the film becomes a polished, professional work, its connections with the historical act of filming, which were so evident in the rushes, gradually disappear. This is especially true of television documentaries, which typically begin with a title sequence whose purpose is to characterize the program as a fully packaged (and therefore predigested) institutional product.
Fourth, there is a loss of internal contextualization . In editing a film to its final length there is an inevitable loss of material which would otherwise clarify and extend the meaning of the material which is retained.
Throughout the editing process there is a constant tension between maintaining the forward impetus of the film and providing enough contextual information so that the central narrative or argument continues to make sense. As the film becomes shorter, the analysis becomes cruder. Film-makers continually sacrifice footage which they know would permit a more complex understanding of the subject but which, for reasons of length, the film cannot afford. To solve this problem, such gaps and elisions are often roughly patched over with spoken voice-over commentary.