Convex optimization of optimization problem is convex. "Standard form" is the usual and perhaps most intuitive form of describing a convex minimization problem. It consists of the following three parts: A convex minimization problem in standard form is thus written as In reality, this form of problem is exactly equivalent to a problem constrained by only equalities. You can rephrase the problem without equality constraints by replacing each equality constraint formula_52 with a pair of inequality constraints formula_64 and formula_65, and the previous analysis holds. This fact is why formula_53 being both convex and concave, i.e. both formula_53 and formula_68 are convex,
Telecentric lens Telecentric lens A telecentric lens is a compound lens that has its entrance or exit pupil at infinity; in the prior case, this produces an orthographic view of the subject. This means that the chief rays (oblique rays that pass through the center of the aperture stop) are parallel to the optical axis in front of or behind the system, respectively. The simplest way to make a lens telecentric is to put the aperture stop at one of the lens's focal points. An entrance pupil at infinity makes the lens object-space telecentric. Such lenses are used in machine vision systems