Here in California, the legislature just passed a bill the governor is expected to sign, and it may affect you. Note, this may affect you if you are a California business (including sole props) OR if you ever do business in California, like, say, a photo shoot here, even if you are a Kentucky business.
This new law (assuming it is signed) codifies a California Supreme Court decision and, basically, says that most workers are employees, not independent contractors. That means that all the labor laws apply to those workers, including minimum wage, workers compensation insurance, payment schedules, and so much more. See my post on paying your people ON TIME for one important part.
The new law specifically carves our exceptions for many creative professions, including graphic designers, fine artists, photographers (with some conditions, more below), and writers/editors/cartoonists (also with similar conditions). But don’t try to shoehorn your crew into these exceptions—it just won’t fly.
As for the exceptions’ conditions mentioned above, the main one is if you make more than 35 “submissions” to a single hiring entity per year, then you are an employee of that entity. “Submissions” means, for photographers, essentially an entire shoot—not singular images. So, if you shoot for Company X for 5 days, that would be a single submission for the 35 count. For writers (etc.), submission is pretty poorly defined but, roughly, it seems to be that submissions on a singular topic or issue, like a series on women in prison made up of 5 articles, would be one submission for the 35 count.
Short answer: California law in this area is very complex and if you aren’t sure what’s what, please talk to an attorney. You don’t want to face the consequences if you are a hiring entity that mis-characterizes your workers, even temporary ones—those costs will be much higher than paying an attorney for advice up-front.
Finally, although I’m writing about California law in this post, I have to say that even if your state does not have laws requiring paying your crew as employees, you really ought to. Is it a pain in the ass? Does it cost your business more money? Yes, to both (you do get tax write-offs, though), but it is the right thing ethically, in my opinion.