A shallow depth of field in photography and videography is when your subject is in focus and your background is out of focus. It is a technique used to bring the viewer's attention to your subject.
DOF stands for depth of field. There are three main factors:
- Distance to the Subject
- Aperture
- Focal Length
A shallow depth can be achieved by the following...
- Shorten your distance to the Subject
- Open your aperture as wide as you can. (Use a small "F stop").
- Use a lens with a larger focal length - or if you are using a telliphoto zoom lens, zoom in. However, to fit the frame nicely with a large focal length lens, your subject may have to stand further away - which defeats this method (see Method 1).
This video explains the concepts.
Thanks to Dylan Bennett and Ling talfi for the illustrations.