Depth of Field is how much of a given photograph is in sharp focus from the foreground of what’s in your frame to the background. Only what your focus point is on (shown as a square or dot when you look through the view finder) will be razor sharp. Other elements in front of (closer to you) and behind (further away from you) will be somewhat sharp. A “shallow” depth of field means a limited part of the photo is in sharp focus. “Extensive” depth of field means most or all of the photo is in sharp focus.
Why Should You Care?
Because it impacts both the camera’s ability to get a particular shot and the esthetic quality of the photograph. Does your camera have a depth-of-field preview button? If so, press and hold it down to check the actual depth of field before you press the shutter. This makes the image very dark in the viewfinder, but it shows how the background sharpness changes as you make adjustments to your settings.
Factors that Control Depth of Field
- Focal Length – a long lens (such as 300-600mm) produces shallow depth of field. A short lens (such as 28-35mm) produces extensive depth of field. A long lens enables you to get a close up photo, isolate the subject from its surroundings, compress the scene and is great for wildlife portraits.
- Subject Distance – As you get closer to the subject, depth of field decreases to fractions of an inch. That means very little in the frame will be in sharp focus.
- Focus Point – Depth of field extends about 1/3 in front of the focus point, and 2/3 behind it. Focus on the eye of the tiger and its nose will likely be focus. However, when photographing an animal with a long face (such as a wolf) and up close, try to photograph their profile to ensure their eye and nose is in sharp focus.
- Aperture (f-stop) – Small f-stops such as f/4 produce limited or shallow depth of field. Large f-stops such as f/22 increase the zone of what is in sharp focus. Wildlife photographers tend to like shallow depth of field so use the smaller f-stops.