What does "depth of focus" refer to?

Depth of focus refers to the distance within which an image remains acceptably sharp. This concept is crucial in photography, especially when determining how much of the scene in front of and behind the point of focus will appear clear in a photograph. A greater depth of focus allows more of the subject and its surroundings to be in acceptable focus, which is particularly important in landscape photography or when photographing scenes with multiple subjects at varying distances from the camera.

In practice, this means that when you adjust your aperture settings, the depth of focus will change, which affects how much of your image is sharp. A smaller aperture (higher f-number) increases the depth of focus, allowing more of the image to appear sharp, while a larger aperture (lower f-number) creates a shallower depth of focus, isolating the subject against a beautifully blurred background. Understanding depth of focus is essential for photographers who want to control the intricacies of image sharpness and composition.