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A lens is a transmissive optical device that focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (elements), usually arranged along a common axis.
Thin Lenses and Ray Tracing. Ray tracing is the technique of determining or following (tracing) the paths that light rays take. Experiments, as well as our own experiences, show that when light interacts with objects several times as large as its wavelength, it travels in straight lines and acts like a ray. (A ray is simply a straight line that ...
Trivex lenses. Trivex, a new lightweight and impact-resistant eyeglass lens material, was introduced in 2001. Trivex lenses are a good alternative to polycarbonate lenses. They are lightweight and have slightly different optical and impact resistance qualities. [Read more about Trivex vs. polycarbonate lenses.]
Single lenses are used in eyeglasses, contact lenses, pocket magnifiers, projection condensers, signal lights, viewfinders, and on simple box cameras. More often a number of lenses made of different materials are combined together as a compound lens in a tube to permit the correction of aberrations. Compound lenses are used in such instruments ...
Progressive lenses are advanced, line-free multifocal lenses that provide more natural vision than bifocals and trifocals for people over age 40. Here's why. Polycarbonate vs. Trivex eyeglass lenses. Polycarbonate and Trivex lenses are lightweight and have similar properties. Find out which is best for you.
Photo: A convex lens makes parallel light rays converge (come together) at the focal point or focus. The distance from the center of the lens to the focal point is the focal length of the lens. The focal point is on the opposite side of the lens to that from which the light rays originate.
Other lenses are zoom lenses, meaning that they cover a range of focal lengths. For example, the most common zoom lens on the market is an 18-55mm kit lens (sometimes 18-50mm or similar). These lenses zoom from a relatively wide angle (18mm) to a moderate telephoto (55mm).
RF Lenses. Designed specifically for our mirrorless EOS R series cameras, these lenses feature high-speed communication and are lighter and smaller to perfectly complement the camera's compact size. They also feature a control ring for added customization and control and offer compatible mount adapters for easy use with filters.
About Camera Lenses. Along with the camera, the lens is a key piece of equipment for photography. At a very basic level, lenses allow you to focus light onto a sensor or film and produce a clear and sharp image of the scene in front of you. Lenses also let you adjust exposure, modify the plane of focus, and different focal lengths can be used ...
Here are a few reasons why you might choose this eyeglasses lens material: Hi-index lenses can correct vision with less material, making the lens much thinner. The plastics are graded in numbers—for example, 1.50 or 1.67. The higher the number, the thinner the lens. Since the lenses are thinner, hi-index lenses are also lighter and more ...