Understanding depth of field will give you the power to decide which part of the photo you need in focus to tell the story you want. Whether you choose to capture detail from the foreground to the horizon or to blur background and foreground distractions to focus the viewer’s attention on a specific spot, your decision will have an impact on what you want to tell. But most importantly, it will effect on how you do it. So let me recap the meaning before digging deeper.
Depth of field (DOF),
Also called focus range or effective focus range, is the distance between the nearest and farthest objects in a scene that appear acceptably sharp in an image. Although a lens can precisely focus at only one distance at any time, the decrease in sharpness is gradual on each side of the focused distance, so that within the DOF, the “unsharpness” is imperceptible under normal viewing conditions.
For a given subject framing and camera position, the DOF is controlled by the lens aperture diameter, which is usually specified as the f-number or f-stop and is the ratio of lens focal length to aperture diameter. Reducing the aperture diameter (increasing the f-number) increases the DOF.
Just remember big f-stop such as f22 will give you a much deeper depth of field from front to back in an image, compared to a smaller f-stop such as f4
Download my quick start guide on Depth of Field for more information.