FORFARANDE OCH ANORDNING FOR ATT DETEKTERA FERGER HOS EN LJUSKELLA

摘要

With the coloured filters inserted in sequence between the light source and the eye of an observer, the colour may be determined by an exclusion process. Red (21) and green (22) filters are used. - The red filter is applied to a lens (41), whilst the green filter is fitted to a second lend (42) of a pair of binoculars (5). The filters are located in a cylindrical casing one side of which is provided with an elastic collar which is pushed over the respective lenses when the filters are fitted to the binoculars.