aperture

Back to Basics - Depth Of Field

depth_of_fieldAfter discussing exposure in great detail, I would like to turn to a different kind of control - Depth Of Field (A.K.A. DOF). OK. Don't jump - you are right. Depth Of Field is not a real control, but more of a result of how you used the aperture control.

In simple words Depth of field is the term you use to describe what is inside the focused area of your image and what is left outside of the focused area (and will stay home alone, and eat dry bread and drink stale water. Sorry Jewish mom syndrome...)

As I said before the control that has the most impact on depth of field is aperture. Bigger apertures tend to provide shallower depth of field. That means that if you open a wide aperture (say f/1.8) you will have a narrow location in your image which is focused. If you set your aperture to a small value, say f/22, you will have a huge focused area. The other two controls you can employ to control depth of field are Zoom focal length and camera to object distance. Click to continue ›

Back to Basics - Aperture

Aperture tutorialAperture is one of the three main controls you can use when you are taking a picture. Along with shutter speed and ISO, aperture controls how light will hit the sensor (OK, old schoolers - hit the film).

In very simple words, aperture is the "size" of the hole the light goes through when it passes the lens. So large apertures will let more light go through then small apertures. Going back to the pipe allegory analogy, we can see the following: If we use smaller aperture, then to keep our exposure unchanged we have to use longer shutter speed, or higher ISO.

Sink image by Andrew Mason. Click to continue ›