Every camera lens produces an image circle, and the size of this circle is called coverage. The coverage of an image circle must be large enough to cover the sensor or film being used. Lens Format Coverage indicates which type of sensor or film a particular lens can cover.

Lenses can be classified as either Zoom or Prime. Zoom lenses have a variable focal length (and thus field of view) that can be adjusted by the user. Prime lenses have a single (fixed) focal length that cannot be adjusted.

Lens Type indicates whether a lens is zoom or prime (fixed) lens, as well as its general focal length and field of view.

The Fixed Focal Length of a prime lens indicates its field of view. Lower focal lengths deliver a wider field of view, while higher focal lengths indicate a narrower (telephoto) field of view.

Zoom lenses provide a range of adjustable Focal Lengths within a single lens. Adjusting the focal length changes the field of view, with lower focal lengths producing a wider field of view, and higher focal lengths producing a narrower (telephoto) field of view.

Certain lenses are designed for specialized shooting applications, such as Macro lenses for close-up shooting, Tilt-Shift/PC lenses for architecture and interiors, and so on.

The Focus Type of a lens is its method of focus. Manual Focus: The user adjusts the focus of the lens. Autofocus: The camera automatically adjusts the focus of the lens. Built-In Autofocus: The autofocus motor is built into the camera lens.

Maximum Aperture indicates the widest opening a lens is capable of and thus how bright or fast it is. Measured in f/stops, the size of the aperture represents how much light is passed through the lens and onto the sensor or film. The lower the f/stop, the wider the aperture.

Lens Series are brand-name groups of lenses with unique sets of designs, features, or capabilities.