Lenses are used in cameras, telescopes, binoculars, microscopes and corrective glasses. A lens can be converging (convex) or diverging (concave).

Focal length is the distance between the optical center of the lens and the point where it focuses the light coming into the lens (when a shot is in focus, that’s the image sensor or film). The ...

Physicists have demonstrated a new type of tunable liquid lens whose focus can be changed simply by varying the pressure on it. The lens is formed from the curved interface between a liquid and air at ...

Their measurements show that the lens resolves details as small as 1/80 of the wavelength of the monopoles. What’s more it has the potential to be much better and work at other frequencies.