Robert Cornelius, 1864 (publication), Fig. 8 (the use of reflectors by Robert Cornelius in Philadelphia), Engraving, Google Books, LL/34860
Robert Cornelius 1864 (publication) Fig. 8 (the use of reflectors by Robert Cornelius in Philadelphia)
Engraving Google Books Published in "The Camera and the Pencil; or the Heliographic Art" by M.A. Root (Philadelphia: M.A. Root, Philadelphia: J.B. Lippincott, New York: D. Appleton, 1864), p.358-359.
The first Philadelphian who produced portraits, was Robert Cornelius. Importing his lenses, he himself manufactured the cameras, plates, and mats, he employed. For coating the plates, he used dry iodine exclusively; and by several large reflectors, set at different angles, both within doors and without, he was enabled, in strong sunshine, to concentrate upon his sitter light enough to obtain through a side-window facing south, an impression within from one to five minutes. (See Fig. 8.) Mr. Cornelius obtained much of his knowledge of the proper mode of proceeding, e. g. the arrangement of lights and shadows, the use of reflectors, &c., from a visit to the rooms of Wolcott & Johnson, corner of Chambers Street and Broadway, New York. These gentlemen were taking portraits at the date of this visit, which (Mr. Johnson thinks) was early in April, 1840, and theirs were the first rooms open for portraiture in the United States. Meanwhile Dr. Goddard, privately experimenting for the discovery of an accelerator, had, with bromine, gotten views, and even portraits, in the open air instantaneously.
Subsequent to this discovery of his, Mr. Cornelius, with bromide of iodine, procured fair impressions, even without reflectors, in from ten to sixty seconds and this too within doors.