Although photography was only invented in the 1820s, it could easily have been invented much earlier. The camera obscure dates back to the time of the ancient greek, early magnifying glasses are recorded dating back to 400 BC, lenses were rediscovered in the 12th century and silver nitrate was discovered in the 12th century. Thus, photography could easily have been discovered in the Middle Ages, but never was. Let's say that in this alternate timeline, photography is invented hundreds of year before OTL. What are the changes? How does it affect history?