Moses Billings
With the development of the daguerreotype in the 1840s, the role of the portrait painter declined in general, because it was now much easier and much cheaper to have one's likeness presented in a visual format. While many portrait painters lost business in competition with the daguerreotype, Billings instead began to produce daguerreotype prints himself. It is not known exactly which prints were made by Moses Billings, as daguerreotypes were usually signed, when signed at all, along the side of the plate. Due to the traditional storing methods of daguerreotype plates, even this signature usually quickly became illegible. However, it has been generally noted, or at least hypothesized, that his daguerreotype prints showed a level of talent and artistry above that of amateur daguerreotypists. Though it is not known exactly which prints were his, it is known that he had largely abandoned the process by the 1850s. Even after he stopped making daguerreotypes, he did continue to paint people's portraits on canvas.
Daguerreotype
The other major innovation was a chemical one. In Daguerre's original process, the plate was sensitized by exposure to iodine fumes alone. A breakthrough came with the discovery that when exposure to bromine or chlorine fumes was correctly combined with this, the sensitivity of the plate could be greatly increased, which in turn greatly reduced the required exposure time to between fifteen and thirty seconds in favorable lighting conditions, according to Eder. Several experimenters discovered the propensity of using chlorine and bromine in addition to iodine: Wolcott, whose "Wolcott's mixture" was marketed by his partner, John Johnson that they called "quickstuff"; two unrelated individuals with the surname Goddard – Philadelphia physician and chemist Paul Beck Goddard, and John Frederick Goddard who lectured at the Adelaide Gallery before assisting Beard with setting up the first daguerreotype portraiture studio on the roof of the Regent Street Polytechnic; (John Frederick Goddard was the first to publish information that bromine increased the sensitivity of daguerreotype plates in the "Literary Gazette" of 12 December 1840) and in Vienna: Krachowila and the Natterer brothers.