Depth of Field

Do you know what depth of field is? It is actually the amount of distance between the nearest and the farthest objects that appear sharp in focus in a photo. The depth of field can be easily controlled using your aperture.

Now is the time to tell you the magic behind those front object clear and background blur magic. Before that, you should also know that DOF or 'bokeh' also represent depth of field in short. You should adjust the depth of field of your picture based on what you would like to focus. Usually in portraits you would sure like to have the person in the picture much sharper than the background because the subject (which is the human) is much more important.

Depth of field is actually manipulated by 3 factors which are: aperture, lens focal length and shooting distance. To get a deeper depth of field (the subject is sharp in focus and the back ground is totally blurred off), your aperture must be as small as possible. An example will be using f2.8 will get a deeper depth of field than using f5.6. Next is the shorter the lens focal length, the deeper the depth of field you will obtain. For example, a 28mm lens will have deeper depth of field compare to a 50mm lens if the same aperture and shooting distance is used. The last method to have a deeper depth of field is to have a greater shooting distance. You will be able to test this result using a telephoto lens. At 135mm you are able to separate the background and the foreground easily even at f5.6.

Basically what the image above is trying to say is just that the object within the accepted range of focus will be sharp while those that are not in range will be blur. This how actually 'bokeh' is created.

A visual example would be something like below:

F2.8

F3.5

F5.6

F8

F11

F13

Did you see that the depth of field of the picture is getting shallower? The back ground and the subject finally became clear and the whole picture is in focus. (the ISO and shutter speed has been varied to get a correctly exposed photo) The main thing about the photograph taken is the lens focal length is kept at 25mm and the shooting distance is fixed for all the photo.

So now you learnt how to put the 'bokeh' in your picture. So go try it out and share your experience with me by leaving a comment. Happy shooting. :)