There's more to buoyancy control than what they taught you in Open Water class. While you can make some incremental improvements in buoyancy control by just diving, you can also ingrain bad habits that you've developed over the course of your past several dives. Buoyancy control isn't just about neutral buoyancy ... it's also about being in proper trim, being properly weighted ... and knowing how to do a weight check, using your "internal bcd" to control your position in the water (especially important for photography), and distributing your weights in such a way that you're not constantly fighting to keep your feet, head, and torso in the correct position. A properly taught PPB class will show you how to do all those things, and why they're important to good buoyancy control. Thinking you can just learn all that on your own is like thinking you can just pick up a guitar, take a few beginner lessons, and become the next Eric Clapton by simply playing. Yeah ... maybe ... but the odds are against it, and you'll make a bunch of mistakes along the way that you don't have to make.
Don't even THINK about picking up a camera until you've developed your buoyancy skills to the point where you don't have to actively think about them anymore ... because if you're still thinking about them, and you try taking pictures, your other skills are going to suffer due to task-loading.
And also, before you pick up a camera, develop another skill ... that of turning your head to look around. Putting on a scuba mask removes your peripheral vision, and therefore you have to develop that habit in order to see what's going on around you. New divers, in general, suffer from lack of awareness because we're used to relying on peripheral vision to see what's going on around us. Taken away, we either learn how to look around habitually or we lose that ability (not to mention lose our dive buddy from time to time). Add a camera into that situation and your awareness of everything else going on around you drops to near zero ... you're effectively solo diving, which (IMO) nobody at your experience level should be doing.
Leave the camera out of it for now. As BDSC says, put some money away for it, but consider it a future investment. Develop a good skills foundation before you make the purchase, though. Buoyancy control and awareness skills are the top two things you should develop solidly before you even think about it ...
... Bob (Grateful Diver)