Editing is regarded by many filmmakers as the single most important step in determining the look and shape of the finished film. The editing process is the one phase of the production that is truly unique to motion pictures. Every other aspect of filmaking originated in a different medium than film(photography, art, direction, writing) but editing is the one process, which has often had an transformative effect on film. A good editor can save a film that has been directed in mediocre fashion, and poor editing can damage the work of even the finest directors.
What Is Editing?
Editing is the work of splicing together shots to assemble the finished film. Editors select the best shots from the large amount of footage the director and cinematographer have provided, assemble them in order, and splice them together. The amount of authority that the editor has may vary from production to production, and the relationship with director.
Functions of Editing
The reason it is difficult to point out the editing's contribution to a specific film is that the audience simply doesn't notice it. We may notice spectacular transitions from one scene to another; you react to them, but you can't really perceive them.
When filmmakers hear how theorists describe "the process of film creation," it always sounds as if every step of the process is carefully planned and constructed. The filmmakers know how accidental or circumstantial film-making really is, to say nothing of how unaware most filmmakers are of their reasons for doing what they do, when they work. Editing is one of those kinds.
Dede Allen, an American editor has given us a best view on editing:
"When I start cutting a movie, I always cut with mixed feelings. I have a definite intention, a definite starting point: the dramatic function of the scene;. the psychology of the characters, etc. But when I become absorbed in the material, I suddenly see all the possibilities the material contains. The unexpected. Intended and unintended possibilities. I can't help wandering into the material. I milk the material for all the small possibilities I see in it. A look, a smile - after the director has said "cut!". Afterwards I form a general view again. But it is in the collision between the general strategy and the pleasant distractions along the way that constitutes editing as art; the true life of the film."
Film Editing is truly a hidden art.