Final answer:
Louis Daguerre developed the daguerreotype process in 1839, a major milestone in photographic technology that improved exposure times and image permanence.
Step-by-step explanation:
The developer of the daguerreotype process was Louis Daguerre. In 1839, Louis Daguerre significantly improved upon the early photographic processes that had been experimented with following the work of Niépce. Daguerre's invention led to a reduction in exposure time and allowed for the creation of a lasting photographic image, although it was limited to producing a single image per exposure. This breakthrough is considered a major milestone in technological improvements in photography.