Friday, January 14, 2011

Understanding Depth of Field

Depth of Field (DOF)
Depth of Field is the amount of distance between the nearest and farthest objects that appear in acceptably sharp focus in a photograph. One can think of DOF like drawing for the first time. When you first begin to draw your images are usually flat looking, for example drawing a triangle. The triangle is flat, and once you get better at drawing you learn how to make it 3-Dimensional... followed by being able to draw a pyramid with an appearance of a town/mountains/people in the background. 
This photo shows good DOF by having the first person in focus followed by other people/objects in the back, adding depth and significance to the picture.
The picture above is one way to represent how DOF can be played with a landscape photo. Many times DOF is strongly shown during a portrait/headshot photo. Many people want to have that "background blurriness" effect called Bokeh. The way Bokeh is achieved is by having a high F-stop number and as most photographer say, "wide open". When somebody is talking about shooting wide open they are referring to shooting with their Aperture low in number, allowing a lot of light to come in. These low numbers are usually F/2.8, but can get down to F/1.4 or lower.

The more open your lens is, the more DOF you're going to have.
-F/1.4-F/4 = A lot of light in, focus on 1 thing, a lot of DOF
-F/5-F/12 = Less light in, many things in focus, less DOF
-F/12-F/22 = Little light in, everything in focus (mostly), little DOF

This photo was taken with prime 50mm at F/2.0. Shooting so wide open allowed for a lot of light to come in and allowed for me to focus on just the one subject (the little girl). 
If I were to have shot this photo above with the same shutter speed but with at F/16 then you would have seen her and bushes/flowers in the background ALL in focus and clear. But having the option to shoot at F/2 I was able to have good DOF and Bokeh.

Below is an example of BAD DOF

This photo* is an example of bad DOF. Everything is sharp, there appears to be no background other than the clouds, and it looks flat (not 3-Dimensional). 


No comments:

Post a Comment