Search results
Results from the WOW.Com Content Network
Radius of curvature sign convention for optical design. Radius of curvature (ROC) has specific meaning and sign convention in optical design. A spherical lens or mirror surface has a center of curvature located either along or decentered from the system local optical axis. The vertex of the lens
An extended hemispherical lens is a special type of plano-convex lens, in which the lens's curved surface is a full hemisphere and the lens is much thicker than the radius of curvature. Another extreme case of a thick convex lens is a ball lens, whose shape is completely round. When used in novelty photography it is often called a "lensball".
In physics, a sign convention is a choice of the physical significance of signs (plus or minus) for a set of quantities, in a case where the choice of sign is arbitrary. . "Arbitrary" here means that the same physical system can be correctly described using different choices for the signs, as long as one set of definitions is used consiste
The signs are reversed for the back surface of the lens: R 2 is positive if the surface is concave, and negative if it is convex. This is an arbitrary sign convention; some authors choose different signs for the radii, which changes the equation for the focal length. For a thin lens, d is much smaller than one of the radii of curvature (either ...
TOKYO (Reuters) -Japanese lens maker Hoya Corp on Thursday said the production of several of its products have stopped after a system failure, which was "most likely caused by unauthorised access ...
In mathematics, the signature (v, p, r) [clarification needed] of a metric tensor g (or equivalently, a real quadratic form thought of as a real symmetric bilinear form on a finite-dimensional vector space) is the number (counted with multiplicity) of positive, negative and zero eigenvalues of the real symmetric matrix g ab of the metric tensor with respect to a basis.
There is not a very clear distinguishing line between camera producers and lens producers; many companies do both, or have done both at one time or another. Some camera manufacturers sell lenses made by others as their own, in an OEM arrangement. Some camera makers design lenses but outsource manufacture. Some lens makers have cameras made to ...
By convention, "f / #" is treated as a single symbol, and specific values of f / # are written by replacing the number sign with the value. The two ways to increase the f-stop are to either decrease the diameter of the entrance pupil or change to a longer focal length (in the case of a zoom lens , this can be done by simply adjusting the lens).