Google is letting me down, and I don't have this in my bookmarks, so I hope I can ask the community for help.
Some racing game studio (Forza??) had a write-up on their production workflow, and they discussed things like taking lots of photos. The games are location based, all I can recall is Berlin.
The write-up mentions that if you see people taking pictures of manhole covers, it's probably one of their artists at work (or something along those lines).
I have looked through the PC wiki and searched (cursory) through the forums, and came up empty.
If the above rings any bells, or better yet if you have a link you can share, that would be awesome!
Thx