Theme: Depth of Field
We are getting a little technical this week using depth of field in composition.
So what does Depth of Field (DOF) mean?
Basically the term refers to the focal distance within the picture plane. When you focus your camera on a point in space within your frame, the foreground, middle or background, you are choosing the depth of field. If you use auto settings your camera will probably give you the longest depth of field it can, making everything appear in focus but what if you want some areas blurred or out of focus? Now comes the teckky part...
DOF is determined by your camera's aperture settings. Think of aperture like the iris of your eye, opening your pupil to allow more light or constricting it to allow less light into your eye.
Aperture settings are called f/stops and are set up like this- the higher the number, the smaller the aperture opening is. I know, it doesn't make sense to me either...anyway...
Higher f/stops or smaller openings also produce the longest focal planes or DOF so for those landscape shots where you want everything in focus, you would use something like f/16 or higher.
Smaller f/stops are wider apertures or openings and produce narrow DOFs. Again, I know it doesn't make sense, but it has to do with the way light refracts from the aperture edges into the camera sensor or film. Suffice to say if you want a narrow DOF with some areas in focus and others not, you will need a smaller f/stop.
Depth of field can be a bit tricky to understand however, as with anything, lots of practice and lots of mistakes are the best ways to learn.
- Remember that a big f/stop is a small opening that creates wider DOF.
- A small f/stop is a big opening that creates a narrow DOF with some areas of blur or less focus.
- Think about the main subject or idea of your image and try to use DOF to enhance your meaning. For example, use blur to remove any unnecessary detail.