lenses [2]
Lenses are characterized by their focal length (between the optical center and the film), aperture (ratio between the diameter of the lens and the focal length) and angle of view (width of the captured image).
macro lens 
Lens designed mainly for close-up shots of small objects.
wide-angle lens 
Lens with a short focal length that covers a larger visual field than a regular lens and provides significant depth of field.
semi-fisheye lens 
Lens with a short focal length that covers a wide visual field; it emphasizes the effect of perspective.
telephoto lens 
Lens with a long focal length that enlarges the image of a distant subject but reduces the visual field and the depth of field.
fisheye lens 
Lens with a very short focal length that covers a visual field of at least a 180o; it creates circular images.
zoom lens 
Lens with a variable focal length so that the visual field can be changed without changing the lens.