Final answer:
Louis-Jacques Mandé Daguerre invented the daguerreotype process in 1839, producing detailed images like the notable Paris Boulevard photograph.
Step-by-step explanation:
The person who developed the daguerreotype process and produced pictures with remarkable detail and rich, harmonious effects was Louis-Jacques Mandé Daguerre. The daguerreotype, a predecessor to modern photography, was a groundbreaking photographic process invented in 1839, which was capable of capturing finely detailed images after a significantly reduced exposure time compared to earlier methods. It was an important step in the history of photography as it allowed for the creation of lasting images, although it could only produce a single image and was not reproducible. Daguerre's work, including his famous photograph Paris Boulevard, showcased the capabilities of this new technology in capturing the essence and detail of a moment in time.