A cylindrical piece of glass or plastic that receives and focuses light to form an image. Most cameras list an f-number and focal length for each lens.
- F-Number: Indicates the size of the lens opening (aperture).
- Focal Length: The distance between the image sensor and the optical center of the lens.
- Lens Adapter: Allows photographers to use special lens attachments (Macro, Zoom, Filters, etc.) on certain cameras.