Here are some basics to know before choosing a lens. Focal length and angle of view Full frame and APS-C A-mounts and E-mounts Lens names and model numbers The focal length extends from the center of ...

The lens in a camera is like an eye that lets light into the camera body and focuses it on the sensor, where the image is recorded. The larger the optical components (known as ‘elements’) in the lens, ...

The great potential of contact lenses for improving vision in all forms of corneal irregularities, e. g. keratoconus, after keratoplasty, after keratitis, is in danger of being forgotten. Especially ...