I never check bags unless absolutely necessary. I have always managed to cram all of my dive gear into a carry-on. For reference, I use an Osprey Porter 46 travel backpack. It has fit into the overhead compartment of every aircraft I have been on, both domestic and international flights. I can fit my Scubapro Hydros Pro BCD, a 3mm full wetsuit, booties (I use low-cut Mares Equator booties for tropical diving, so they are small and rather flexible), my mask (no box - just wrap it carefully in a rashguard), regs, primary and backup dive lights, GoPro, a rolled-up dry bag for the boat, and two pairs of boardshorts and a couple of t-shirts. The backpack has two horizontal cinch straps that go across the front of the bag, and I use them to lash my fins to the outside of the bag. I also have a lightweight mesh bag that I roll up and cram inside. I've never had a gate agent give my bag a second glance, but in the off-chance that I get flagged to gate check my bag, I can use the mesh bag to offload my fins, regs, mask, and whatever other fragile equipment I would rather carry-on. My computer is a watch-size, so I just wear that. Depending on the size of your camera equipment, you could perhaps pack that in a small hand-held case that would count as your personal item.
There are times when I think that it would be easier to check most of my gear and just carry a small bag with my regs onboard, but then inevitably I get to my destination and find that one of my dive buddies had their gear delayed. So I just deal with hauling my backpack through airports and connections.