In addition to using a 360 camera on set, we also had a fisheye lens to take HDRIs with. It was an 8mm lens that seems to capture beyond 180 degrees. Using a tripod head that locks in set positions, we were able to capture two sets of bracketed exposures directly opposite of each other.

Then, in Nuke, I used SphericalTransform nodes to stitch them together. They didn’t line up perfectly, so I had to do some shifting of the images. The camera’s sensor also cropped off the top and bottom of the image which required some inpainting and manual fixes. The stitching is still not as clean as the one from the 360 camera, however the image quality and dynamic range are much better.