The holophotal arrangements proposed in 1849-50 show the modes of solving the problem of condensing the whole sphere of diverging rays into a single beam of parallel rays, without any unnecessary reflections or refractions[1]. A holophote is an instrument which intercepts and parallelises all the rays proceeding from a focal point by the minimum number of agents[1].
Get more accurate answers with Super Search, upload files, personalized discovery feed, save searches and contribute to the PandiPedia.
Let's look at alternatives: