TY - JOUR AU1 - Lehmann, H AB - shown how annealing map be perfectly effected in a minimum time. With the apparatus erected in their laboratory Messrs. Hilger are prepared to test specimens for t.he trade. T. F. C. (( 03’ THE THEORY OF OPTICAL INSTRUMENTS WITH AuTo~imIc F’OCUSING OF IMAGE AND OBJXCT.” (ZEIT. fur INST., October).-Dr. H. IAehuiann describes the geometrical construction connecting the successive positions of object itncl image in automatic focusing devices. More than once he acknowledges these are well knoirn in England, but novel in Ger- iiinny. He describes geometrical constructions by Pizxiglielli, Ciirpentier. Killian, and Sainp- snii. and shows lion- t,liey can be applied to ’‘ scissors ’’ linlinorlr or trammels, in one case so accurately that even a final touch by hand is unnecessary. Jllust.rations tire also given of models fov piii*poses of instruction, which show the necert- SRI~ linlrwork to maintain the object and image ill conjugate positions. Enlarging cameras eniboclying similai. prin- ciples are already on the marlcet in this co~ln- try, iind the variable power telesc.ope whicli i~eniains in fociis throughout the changes of iiia,gnification i,s another application. Thc article is to be continued. and will be al,sti.actrd more fully when complete. w. s. TI - On the Theory of Optical Instruments with Automatic Focusing of Image and Object JF - Transactions of the Optical Society DO - 10.1088/1475-4878/17/2/303 DA - 1916-11-01 UR - https://www.deepdyve.com/lp/iop-publishing/on-the-theory-of-optical-instruments-with-automatic-focusing-of-image-xIDdFnx8Ad SP - 73 VL - 17 IS - 2 DP - DeepDyve ER -