This has come up before, but now that I'm a paying customer I thought I'd take a moment and make this request (for v3...): Octane needs a true equidistant, circular fisheye camera with adjustable FOV.
To see how this should work, look directly at Vray's VrayCameraDome. This generates precisely the output we use for almost every single job we render - adding this to Octane is crucial for us to use Octane as a primary renderer. The same will be true for anyone working in fulldome content generation and many others.
We hope to see such a camera in v3, and are indeed desperate for GPU-based tools that can provide the output we need. Fingers crossed.
cpm5280