DSLR Underwater Rig

this will always be a moving target.

The eye focus feature in the R5 works to a degree on fish.   That and 45 MP will drive many there.   Plenty of happy 810/850 and A7III/IV users out there as well.

The lenses and the ports matter more than the camera body.   Pick a camera system and a housing system and go from there.

Mirrorless works well doesn’t need to be a dslr. If you are using live view and the screen I find it easier to compose and safer as you can see what is going on around you. And whether you use auto or manual focus depends on what you are doing as well.

Russell Ord uses a medium format Fuji so it comes down to what you have/like.

what you can’t skimp on is a decent housing, else you will regret it when you get flooded out.

I was asking about housing. Each camera ha its own housing?

Yep they will have different housings. If the button layout changes between the models then a  new housing is needed usually.

Let’s talk “serious” UW photographers, in addition to “professionals”. Until about 5 years ago, there were only DSLRs in use,  mainly Nikon and Canon. Then Sony pioneered quality mirrorless, recently joined by Canon, with Nikon a distant third. Olympus cameras are also in use, but are fading away as Olympus has exited camera manufacturing. All of these brands make quality equipment with Nikons and Canons more in use. DSLRs and mirrorless cameras have separate, interchangeable lenses. You need an underwater housing designed to match the specific layout of the camera controls, which varies between manufacturers and usually between models of a manufacturer. In addition, you need a port to mount on the front of the housing, and each lens typically requires a port unique to that lens and make of housing. This is why you often see complete used systems for sale. If you upgrade to a Sony a7r4, for example, you need a new housing to match the button layout and body dimensions  which differ from those of the a7r3.

there are good plastic housings (Ikelite) but aluminum is more favored (Nauticam, Sea and Sea, etc.). The housing can cost as much as th3 camera body, and then there are ports.

A focus light and dual strobes also are important. Inon and Sea and Sea are two of the more popular brands.

there’re lots of threads and alternate opinions here and other boards.

hope this helps.

I believe that if you are using mobile for underwater photography then Sony is the best brand that I have used. Not sure about cameras though.

If you're asking about the housing brand then you can't go past Nauticam.