Small Depth of Field

Eeyore84

Hello everyone. I've been reading "Nikon D3100 from snapshots to great shots" and I was wondering if any one could explain what a small depth of field is?

ZekeMenuar

In short, small depth of field happens when the aperture is set to a small number like f/1.8.
For example, if you use a pop can as the subject with the aperture set at f/1.8, the can will be in focus but everything behind the can will be out of focus.

If you set the aperture at something like f/10 or higher, then more of the background will be in focus.
In other words, a small "f" number means a shallow depth of field.
A big "f" number mean deeper depth of field.

Depth of field tutorial here:
http://www.cambridgeincolour.com/tutorials/depth-of-field.htm