Here is the definition of a photography nerd from the urban dictionary.
I’ve never had a total of five cameras around my neck. But I have to confess that I carried four at once a couple of times. A DSLR, a GoPro, a video camera, and of course I’ve always got my smart phone.
Photography is your life. Photo Nerds eat, drink, sleep, dream and think about photography every day.
In a sentence:
Check out those three photo nerds, they probably have five cameras each around their necks!!
Source: Urban Dictionary