# What does depth of field mean? [duplicate]

What does the term depth of field mean?

How is it determined and how can it be changed?

Is it related to the aperture?

• Dude, slow down. You are bombarding this site with content that is duplicate of existing content. Use. The. Search. Please. – dpollitt Aug 27 '13 at 22:31
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Depth of field is the amount of the image/subject that is in acceptable focus. Depth of field varies with subject distance and aperture. A larger aperture (lower f numbers) gives shallower depth of field with a given lens. A narrower aperture gives deeper depth of field with that same lens.

Old-school cameras provide a depth of field scale on the lens so that you can tell how much of the subject will be in focus based upon your aperture and focus setting. Modern cameras have dispensed with this important (IMO) feature for the most part.

If you are shooting an SLR, you can see the effect of a given aperture/focus distance by using the depth of field preview button/lever (if your camera has one).

I have done a video over here that covers depth of field, and demonstrates it using a classic lens' depth of field scale:

http://youtu.be/WUMmdnJiUms

• Depth of Field also varies as a function of display size, viewing distance, and the visual acuity of the observer. A digital file printed at the standard 8x10 and viewed at the standard 10 inches will appear to have more depth of field than the exact same digital file printed at 16x20 and viewed at 10 inches by the same person. Depth of Field is a way to describe how large the circle of confusion is before it is not perceived as a single point. – Michael C Mar 2 '14 at 22:42
• One reason DoF scales (which usually assumed the standard 8x10 viewed at 10" by a person with 20/20 vision) are rarely printed on on lenses now is because in the digital age there really is no standard display size and viewing distance any more. Most applications will scale an image to fit the screen on which it is displayed, whether it is a 3" screen or a 60" screen. – Michael C Mar 2 '14 at 22:45

From Cambridge in Colour:

Depth of field refers to the range of distance that appears acceptably sharp. It varies depending on camera type, aperture and focusing distance, although print size and viewing distance can also influence our perception of depth of field

See the link for all the details, but in a nutshell:

• Larger aperture => less depth of field
• Larger sensor => less depth of field
• Larger distance to subject => more depth of field