I kinda don't like blanket statements and DEFINETLY don't like specific dive numbers to be a gauge of anything but how much spare time you have on your hands.
Some people are very comfortable in water, having played around in it their whole life before taking up diving, which come natural to them and get dialed in quick - others are the opposite. There is no "you have 32.7 dives so you can use a camera" textbook answer, unfortunately.
Ay-MEN!
I started to bring a camera below the surface shortly after my OW course. Heck, I even brought it on my last OW course dive, the 6th where we plan and execute the dive and are only supervised by the instructor. The camera lives on my BCD like my backup light and manometer (well, OK, my AI Suunto Cobra) do.
Now, I'm one of those who snorkeled a lot and swam regularly through all of my childhood and youth. I've always been comfortable in the water. I've also been photographing since I was a teenager, the camera I started to do UW photography with was a simple P&S set to auto mode and I was pretty conscious that the photography task was going to be at max my third priority during the dive ("Wow, cool! *click* OK, where's my buddy?"). My photography never took precedence over buoyancy awareness, gas and depth monitoring and buddy contact. And only when I had worked up enough routine to delegate some of those tasks to the back of my mind, I got myself a more "serious" camera rig and allowed the photography task to take up significant space in the front part of my brain. And it's still only second priority WRT my diving.
I've never had complaints from my regular buddy about my photography taking precedence over my diving. Except when I spend too much time at one single subject and he has to wait too long for me
OTOH, I've dived with people who, even without a camera, are a lot worse than me in buddy contact, gas monitoring, bottom time monitoring etc. Even when I'm in full-blown photography mode...
EDIT: What I'm trying to say is perhaps that IMO it all depends on how task loaded you are by just diving, and how much of your mental capacity you allow the secondary task (be it photography, scallop harvesting, spearfishing or other "stuff") to occupy. If you're comfortable in the water and trained enough in the technical aspects of the secondary task to delegate it to the rear part of your brain, I believe you can start doing "stuff" underwater pretty early in your diving career without compromising safety.