 By 1869 Yokoyama, accompanied by friends and students, was travelling throughout Japan to make stereoviews.He produced at least three series of views that were published at the time, but that are now very hard to find.According to photography historian Rob Oechsle, Yokoyama's are the only notable Japanese-made stereographic series from the early Meiji period; they were taken from 1869 through the 1870s.