Photography: more about depth of field
Depth of field, or ability to control the parts of your photographs that is in focus, is on your fingertips when you use your single lense reflex digital camera.
The photographer with depth of field in mind, have the ability to create emphasis where you want it, either to hide elements that will otherwise be distracting or to create a special effect.
A camera can only focus its lens at one single point at a time, but there will be an area in front of and behind this focus point that still appears sharp.
This zone of sharpness is called the photograph’s depth of field.
Depth of field is not a fixed distance, but changes as you use the aperture on your camera.
The aperture, or called f-stop is how you manipulate the light that falls on the sensor.
The aperture that brings the most light to your camera’s sensor is the lowest number on the aperture of your camera.
On my camera this number is 5.6, but it can go lower on other cameras and lenses.
This is described as a shallow depth of field where only a narrow zone appears sharp on the photograph.
The other contrast to the shallow depth of field is called a deep depth of field.
This is when the number on your aperture properties goes to the higher numbers on your aperture.
On my camera the number that allows the smallest amount of light to the sensor is f36, which will give the sharpest picture.
Most cameras have automatic focus points, which we all use, but the spot where the camera focuses don’t neccesarily have to be in the middle of the photograph.
There is a button on our cameras that you can use to manually shift the focus point.
Something to remember is that the success of your photograph is directly linked to the f-stop/shutter speed ratio.
I will write more about shutter speed at a later stage.
Many photographers are uneasy to use the M (manual) button, where you set the camera to your preferance.
Others use the AV button on the camera, where you determine the f-stop and the camera automatically sets the shutter speed.
This is dangerous, because sometimes we get camera shake because of too low shutter speeds.
We get photographers who don’t even think of changing the f-stop to get a depth of field effect.
As a journalist I have seen photojournalists only point and shoot on f8 inAV, which is (as far as I am concerned) the most convenient f-stop for us.
Others take photos on automatic, which is fine if you never want to learn about photography.
