Know your stuff
Controlling your depth of field is a crucial component of photography. How can you use it effectively?
Simply put, depth of field is the area of acceptable sharpness in an image. A deeper field renders more of your image sharp while a shallower field gives you a narrower focus area. This is controlled by the opening through which light rays enter your camera before refracting and converging onto the sensor, onto what is known as a ‘circle of confusion’ (standard lenses can’t converge light to a perfect point). Small apertures (such as f/22) create smaller circles of confusion, making more objects on different planes in your image acceptably sharp. Larger apertures (such as f/4), create bigger circles, which appear as out of focus blur spots. How to use it? Switch the setting to aperture priority mode and focus on your subject. Use a wide aperture to draw attention to and isolate your subject, and a narrow aperture to showcase a whole scene equally, such as a landscape.
A narrow aperture (f/22)
A wide aperture (f/4)