Single lens reflex (SLR) cameras use interchangeable lenses. These lenses give the photographer a variety of focal lengths to work with and creative options for controlling depth of field in the pictures. Each camera lens has a set of common features to make it work effectively.
Zoom Ring
Camera lenses that have a zooming capability (not fixed focal length lenses) are operated by rotating the zoom ring on the barrel of the lens.
Focusing
SLR camera lenses can be focused manually or by using autofocus. Some lenses have a toggle switch on the side to choose manual or auto. If focusing manually, rotate the focusing ring on the barrel of the lens until the desired level of focus is reached.
Front
The front of an SLR camera lens is threaded so it can accept a variety of filters with a thread mount. UV haze filters, sky filters and black and white filters are often attached long term to the front end of a lens to protect the glass and multicoating on the end of the lens.
Rear
The rear of the lens has a series of contact points that align with the body of the SLR camera to transfer data.
Lens Data
On the barrel of the lens the focal range and aperture will be printed. The filter size will be printed on the front end of the lens.
Tags: barrel lens, camera lens, front lens, ring barrel, ring barrel lens, will printed
