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The design of a fixed focal length lens (also known as prime lenses) presents fewer challenges than the design of a zoom lens. A high-quality prime lens whose focal length is about equal to the diameter of the film frame or sensor may be constructed from as few as four separate lens elements, often as pairs on either side of the aperture diaphragm.
Essilor International is a French multinational corporation specialized in the design, manufacture and sale of ophthalmic lenses, optical equipment and instruments. [ 1 ] [ 2 ] It is the world's largest manufacturer of ophthalmic lenses.
This list covers optical lens designs grouped by tasks or overall type. The field of optical lens designing has many variables including the function the lens or group of lenses have to perform, the limits of optical glass because of the index of refraction and dispersion properties, and design constraints including realistic lens element center and edge thicknesses, minimum and maximum air ...
The Multi-Design concept was a first stage of personalization of the progressive lens, a specific optimum design for each age class of the presbyopic wearer. [12] By the end of this decade, Essilor would become the world's leading manufacturer in ophthalmic optical products. [13]
Essilor and Luxottica were respectively the world's leading manufacturers of ophthalmic lenses and of eyeglasses; upon the merger, EssilorLuxottica thus became the juggernaut of the eyewear industry, which some critics have qualified of near monopoly. Essilor contributed its numerous proprietary lens technologies as well as its subsidiaries to ...
A couple of later Minolta lenses do have a built-in ultrasonic focus motor (SSM lenses), like other SLR and DSLR systems (i.e. Canon and Nikon), where the AF computer is inside the camera body and there is a digital interface connecting body to an electric motor and the focusing gears built into the lens body.
Optical lens design is the process of designing a lens to meet a set of performance requirements and constraints, including cost and manufacturing limitations. Parameters include surface profile types (spherical, aspheric, holographic, diffractive, etc.), as well as radius of curvature, distance to the next surface, material type and optionally tilt and decenter.
A lens accessory that fits between the lens and camera body and extends the focal length of the lens, often by 1.4x or 2x, at the cost of reduced light, decreased image quality, and slower autofocus. TCA: Transverse (lateral) chromatic aberration or lateral colour. Colour fringes that worsen the further the image point is from the optical axis ...