Hi Jonathan, If i were you i would go with career and work as a freelancer in photographer or you could also do the reverse.
But since you have got a chance to do what you like then i prefer to go with hobby. You got both the options, its your life and your choice but at the end of the day, you have to take note of all options and pros/cons to weigh your choice.
Make a better choice that wont make you regret later.