Aperture and depth of field - Digital photography
Aperture and depth of field:
The aperture also influences the depth of field. Depth of field determines how much of your photo will be in focus. We will discuss depth of field later in another lesson, so for now the following will be enough to know:
A small aperture gives more depth of field – the image is sharper.
With a bigger aperture the image will be less sharp.
With a big aperture the depth of field will be a lot less.
Automatic cameras and creative shooting functions:
Some automatic cameras have the aperture priority (AV) setting.This means that when the aperture is changed, the camera will automatically adjust the shutter speed.
Where the aperture is small, for example f11 or f16, the shutter speed might be so slow that camera shake will occur.
Make sure to read about the creative shooting settings again here.
The photographer has these 3 choices:
- M (Manual) – photographer sets the aperture and shutter speed.
- A (AV) - photographer chooses the f/stop(aperture) and the camera the shutter speed.
- S (TV) - photographer chooses the shutter speed and the camera the f/stop (aperture)
Influence of ISO on shutter speed and aperture:
It is only since digital photography that the ISO plays such a big role. Before digital photography it was the relationship between the shutter speed and the aperture that determined how a photo would be exposed. Now that the ISO can easily be changed, this setting can be changed pro-actively to get the best possible lighting for a photo.
Remember the aperture determines the depth of field while the shutter speed either freezes the image or shows movement.
By changing the ISO, a photo can be taken in bad lighting situations, for example in sports photography. Just remember that when the ISO is set too high, noise might show on the image.
Editing a photo:
To use photoshop to edit an image, which is underexposed, might show noise on the image. If a photo is overexposed there are not enough colored pixels to darken the image. The best solution is to get the correct exposure from the beginning.
