The photographer controls the f-stop, which determines the depth of field and how much light enters the lens. If the lens focal length is 20mm and the aperture diameter is 10mm, then f-stop = 20mm/10mm = 2. The graphic shows increasing f-stop values with decreasing aperture diameters. The focal length of the lens determines your field of view (composition) and the magnification of the scene. The aperture diameter is the straight distance across the widest part of the aperture. F-stop is the ratio of lens focal length to aperture diameter.į-stop is a dimensionless number, denoted by a hooked “ f ”, with an underlying number denoting the f-stop value.į/2.8 and f/8 are two examples of common f-stop settings, where 2.8 & 8 are the f-stop values, respectively.į-Stop = Lens Focal Length (mm) / Aperture Diameter (mm).Aperture is the opening in the front of the lens where light enters the camera.The terms f-stop and aperture are often used interchangeably, this is incorrect.

Mastering depth of field requires a basic understanding of f-stop, focal length, focus range, and camera lenses. Amount of Light exposed to the image sensor, which controls the image brightness, rated in stops.The entire image between these objects also maintains sharp focus. Depth of Field (DOF) determines the closest and farthest objects in an image, both of which are in focus.In photography, aperture diameter, determined by f-stop, controls two important factors:

F stop vs t stop