Wikipedia said:The Song Dynasty Chinese scientist Shen Kuo (1031–1095) experimented with a camera obscura, and was the first to apply geometrical and quantitative attributes to it in his book of 1088 AD, the Dream Pool Essays.[9][verification needed] However, Shen Kuo alluded to the fact that the Miscellaneous Morsels from Youyang written in about 840 AD by Duan Chengshi (d. 863) during the Tang Dynasty (618–907) mentioned inverting the image of a Chinese pagoda tower beside a seashore.[9] In fact, Shen makes no assertion that he was the first to experiment with such a device.[9] Shen wrote of Cheng's book: "[Miscellaneous Morsels from Youyang] said that the image of the pagoda is inverted because it is beside the sea, and that the sea has that effect. This is nonsense. It is a normal principle that the image is inverted after passing through the small hole."
While it wouldn't be photography, just doing line tracing with the camera would be pretty easy. Wonder why it wasn't done.
Well... while I'd really like to see some photographic examples of what Song Dynasty life was like, I could see Ancient Chinese photography having one major use... as a tool used by imperial concubines to 'attract' the Emperor into their bedchamber, like how the Emperor picked his mate for the night on the basis of court paintings in the legend of Wang Zhaojun.
So while there might be a few photos of military battles and daily Song life lying around in the historical records, the vast, vast majority of the photos would probably just be Chinese girls doing duckface or planking or whatever Song Dynasty people found sexy.
The camera and the Chinese propensity for printing would lead to porn, since China did (and does) have an enormous porn industry.
Of course, this would spread along the Silk Road to other places, resulting in more porn.
It's a technique that allows you to produce very realistic images, while Chinese art traditionally tended much more to the symbolic and tended not to treat perspective in the same way as the west considered it. Not to mention that most traditional art was done as an extension of calligraphy and thus used ink brushes, meaning that line tracing would be difficult anyway.