Types of 360° Video Rigs
There are several types of 360° video rigs available depending on your budget. From simple 2 camera setups with very low resolution, to rigs involving more than 24 GoPro Hero 4 Black cameras, there's certainly a rig out there for your budget and application. The biggest hurdle I faced was a lack of reliable information out there for the budget minded 360° videographer. At first it was just multiple GoPro cameras, and even then they weren't in their waterproof cases, the 360° mounts would be for GoPro's that were out of their cases. Finding rigs and learning how to shoot 360° underwater was particularly challenging as there was almost no information out there on it. And for me, my focus would be underwater of course, and I would learn several very valuable lessons during my introduction to 360° video.
First Rig, with SJ4000's
Lessons Learned on 360° rigs
First lesson is don't go cheap on the cameras. I figured with a 7 camera 3D printed mount I would be able to use the cheaper SJCam SJ4000 cameras, and the problem was these cameras did not have ANY overlap in order to stitch. So I ended up having to get 6 additional GoPro Hero4 Silver cameras (already had one Hero 4 Silver).
Second lesson was you NEED domes for GoPro's to have usable footage underwater, EVEN WITH a 7 camera 3D printed rig. Sure, the ad says the extra camera helps with the stitching underwater, but parallax issues are totally unmanageable underwater. I can achieve flawless stitches above water, even using the waterproof cases, but underwater footage with a 7 camera rig STILL needs domes. I am looking for an old rig made by 360Heros that has smaller domes, and then maybe I can utilize my GoPro's underwater for 360°. Until then, I may play with 3D video, but most likely will just use a single GoPro with my Flip 3.1 lenses and my dive tray.
So, in the quest for decent 4k footage, on a camera that has a dome, I came across the Kodak SP360 4K camera. Two of these cameras back-to-back would give you 360° x 470° footage, so 110° of overlap (That's ALOT!). This pair of cameras came with a second benefit as well. they were light enough to be custom mounted on top of, and below, a DJI Phantom 3 4K drone, to allow for aerial 360° videos, where the drone can be edited out with the 110° of overlap available! So, this simple pair of cameras gives me 4K per camera capability, decent footage with a minimal stitch line on land, decent footage in the air with an almost unnoticeable stitch line, and Kodak even made a dual camera underwater case that allows me to get decent footage while diving, with minimal parallax issues in each situation. Is it the same clarity and resolution of 7 GoPro cameras? Of course not, but for what it is, it's incredible! And quite honestly, it's much more enjoyable editing when I only have 2 cameras / 2 memory cards to deal with instead of 7!
My 360° Rigs
As I mentioned earlier, my very first rig was a 7 camera 3D printed array using SJCam SJ4000 cameras. This did NOT work as the overlap didn't even exist for stitching. The cameras FOV was too small. They do work just fine underwater, however they cannot be used in a 360° rig..
That led to rig #2 which uses 7 GoPro Hero4 Silver cameras with the 3D printed mount from the SJ4000 rig. When I first assembled this rig, and I was able to stitch footage from my back yard with ease, I figured all was good. I had read that the 7th camera in the "cube" added a lot of overlap so you could then film underwater. Not so true, well not without needing some extras like domes. Still a good rig for 360° footage above water, but also somewhat fragile. Use with caution (can't mount it to a helmet cam mount, it would shake to pieces), but do use it for shots where you want a lot of detail and your camera doesn't move much.
Some more research turned up rig #3. This is a pair of Kodak SP360 4K cameras. Yup, you read that right, just a pair of cameras, not 6 or 7 in an array. The way the lenses are on these cameras, it films an area 360° around and 235° over top, so putting two of them back to back gives you 360° x 470° of coverage (which helps a lot in editing when you can mask areas from one cam or another).
Waterproof dive housing for BOTH cameras that is actually affordable ($85!). I have only tested this in shallow water so far, but plan to take it diving in a month and will report on it then. I have no fear that it will allow the cameras to work just fine to 30m, and I am very hopeful that it will do a better job with 360° footage underwater because of the domed lenses.
The buttons have a nice solid feel to them when pressed, and the camera latch has a nice positive lock when the doors are closed and the mount is conveniently located for optimum camera positioning.
The ability to use a drone to capture "floating" 360° shots. I use a DJI Phantom 3 and have mounted 1 camera on the top center, and 1 camera under the landing gear. Of course this means you need to hand launch, and hand land, but with the overlap on the Kodak cameras, I am able to eliminate the Phantom from the footage completely, no landing gear, and no propellers.
I will post more details about my mounting system as I tweak and test it, including specifics on what I used to mount the cameras and a few sample videos.