Photogr. Also focometer. [f. FOC-US + -METER.] An instrument for finding the chemical focus of a lens which has not been properly achromatized.
1853. R. Hunt, Man. Photogr., II. iv. 159. M. Claudet has also devised a very ingenious instrument for focusing, which he calls his Focimeter.
1891. S. P. Thompson, in Proc. R. Soc., XLIX. 226–7. These principles are embodied in an instrument described in the paper, and called a focometer.
