A quadratic cost functional for computing an estimate of a wave front from multiple directional derivatives is presented. This functional is robust to noise and is specially suited for moiré deflectometry, Ronchi testing, and lateral shearing interferometry.
In this paper we present the development of a laboratory prototype to obtain the digitahzation and three-dimensional reconstruction of a solid object applying the laser line projection technique. The object under test is placed on a motorized rotary stage, a diode laser system projects a line on the object, the deformed line pattern is acquired by a CCD camera. The information for its reconstruction is extracted of the bi-dimensional images of the deformation that the laser line suffers according to the three-dimensional topography of the object. The present prototype digitizes an object in approximately 20 seconds without affecting it the ambient illumination.
This article describes a simple Hartmann test data interpretation that can be used to evaluate the performance of ophthalmic lenses. Considering each spot of the Hartmann pattern such as a single test ray, using simple ray tracing analysis, it is possible to calculate the power values from the lens under test at the point corresponding with each spot. The values obtained by this procedure are used to plot the power distribution map of the entire lens. We present the results obtained applying this method with single vision, bifocal, and progressive lenses.
In the classical Hartmann test the wave front is obtained by integration of the transverse aberrations, joining the sampled points by small straight segments, in the so-called Newton integration. This integration is performed along straight lines joining the holes on the Hartmann screen. We propose a modification of this procedure, considering the cells of four holes of the Hartmann screen to fit a small second-power wave front recovering each square. This procedure has some important advantages, as described here.
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