14 Control Your Depth of Focus

Before You Begin

3 About the Camera's Perspective

5 About Reducing Motion and Relying on Your Subjects

11 Zoom Effectively

Beginning videographers rarely think about the subtleties of filmmaking , but it's the little things that can really make your projects look professional and have that extra punch. One such aspect is depth of field . Creative use of depth of field can have a powerful, dramatic role in your films .

Your video's depth of field depends on both the amount of zoom you've set and the current aperture setting ( see 13 Light Your Video Properly ). Use depth of field to isolate your subject from the foreground and background or to keep the entire scene in focus. Unlike the process with a regular 35mm film-based camera, you don't have to do anything to check the depth of field you are filming ; what you see through the viewfinder is what you get on film.

KEY TERM

Depth of field ” The amount of a scene that is completely in sharp focus at any one time.

1. Zoom In for Less Depth
   
   An easy way to reduce depth of field to isolate your subject is to work at the telephoto end of the optical zoom on your camera. However, note that zooming in to the digital zoom ratios on your camera has no effect on depth of field.
   
   

   TIP

   

   The more you zoom in to a subject, the steadier your camera must be to keep camera shakes from the audience's eyes. A tripod works wonders to reduce zoom-in camera shake.

2. Zoom Out for More Depth
   
   You achieve the most depth of field by zooming out to the camera's most wide-angle setting. At this setting, virtually all of the scene should be in sharp focus.
   
   
3. Open Aperture for Less Depth
   
   If you can switch to the camcorder's manual mode, opening the aperture to admit more light also has the effect of reducing depth of field. In this picture, note that although the camera lens is zoomed out to capture both children, the wide-open aperture setting narrows depth of field so that the focus is only on the child in front.
   
   

   

4. Close Aperture for More Depth
   
   In manual exposure mode, if you shut down the aperture to smaller values, you reduce the light entering and simultaneously increase depth of field, putting more of the scene in focus. In this picture, notice that the lens is zoomed out about the same as it was for the children in the preceding step, but the smaller aperture setting forces a deeper field of focus.