Answer:
Calotypes
Step-by-step explanation:
Maxime du Camp was a writer and a photographer from France. Although he wrote many books of various kinds (novels, poetry and more), and was friends with many great French writers of his era, he isn't as much remembered as others.
He did a long Oriental voyage and in preparation for that long trip in a foreign country, he learned photography. He mostly used the calotypes technique created by the British Talbot a few years earlier.
This technique allows to make photograph prints of extreme quality. Many of the photos of Du Camp processed 150 years ago are still of great quality!