From my understanding, the copyright is held by the photographer unless you have a contract stating such. I was shocked that most wedding photographers consider giving up copyright a deal breaker (unless you pay a huge amount more): https://www.reddit.com/r/WeddingPhotography/comments/10esy2i...

edit: If you are working as a employee (think W-2), it is different. Just hiring someone to take pictures (think 1099/contractor), I think is not covered under the same rules.